diff --git a/elixir/apps/domain/lib/domain/cache/client.ex b/elixir/apps/domain/lib/domain/cache/client.ex
index e86720277..03883d79b 100644
--- a/elixir/apps/domain/lib/domain/cache/client.ex
+++ b/elixir/apps/domain/lib/domain/cache/client.ex
@@ -51,7 +51,7 @@ defmodule Domain.Cache.Client do
 
   """
 
-  alias Domain.{Actors, Auth, Clients, Cache, Gateways, Resources, Policies}
+  alias Domain.{Actors, Auth, Clients, Cache, Gateways, Resources, Policies, Version}
   require Logger
   require OpenTelemetry.Tracer
   import Ecto.UUID, only: [dump!: 1, load!: 1]
@@ -159,8 +159,8 @@ defmodule Domain.Cache.Client do
 
     added_ids = Enum.map(added, & &1.id)
 
-    # connlib can handle all resource attribute changes except for changing sites, so we can omit the deleted IDs
-    # of added resources since they'll be updated gracefully.
+    # connlib can handle all resource attribute changes except for changing sites (on older clients),
+    # so we can omit the deleted IDs of added resources since they'll be updated gracefully.
     removed_ids =
       for r <- cache.connectable_resources -- connectable_resources,
           toggle or r.id not in added_ids do
@@ -273,9 +273,11 @@ defmodule Domain.Cache.Client do
 
     cache = %{cache | resources: resources}
 
+    toggle = Version.resource_cannot_change_sites_on_client?(client)
+
     # For these updates we need to make sure the resource is toggled deleted then created.
     # See https://github.com/firezone/firezone/issues/9881
-    recompute_connectable_resources(cache, client, toggle: true)
+    recompute_connectable_resources(cache, client, toggle: toggle)
   end
 
   @doc """
diff --git a/elixir/apps/domain/lib/domain/component_versions.ex b/elixir/apps/domain/lib/domain/component_versions.ex
index 9459551ca..8fe84fbdb 100644
--- a/elixir/apps/domain/lib/domain/component_versions.ex
+++ b/elixir/apps/domain/lib/domain/component_versions.ex
@@ -58,6 +58,16 @@ defmodule Domain.ComponentVersions do
     end
   end
 
+  def get_component_type(%Client{last_seen_user_agent: "Mac OS" <> _rest}), do: :apple
+  def get_component_type(%Client{last_seen_user_agent: "iOS" <> _rest}), do: :apple
+
+  def get_component_type(%Client{last_seen_user_agent: "Android" <> _rest}),
+    do: :android
+
+  def get_component_type(%Client{actor: %Actor{type: :service_account}}), do: :headless
+
+  def get_component_type(_), do: :gui
+
   defp fetch_config! do
     Domain.Config.fetch_env!(:domain, __MODULE__)
   end
@@ -98,14 +108,4 @@ defmodule Domain.ComponentVersions do
         |> Keyword.fetch!(:versions)
     end
   end
-
-  defp get_component_type(%Client{last_seen_user_agent: "Mac OS" <> _rest}), do: :apple
-  defp get_component_type(%Client{last_seen_user_agent: "iOS" <> _rest}), do: :apple
-
-  defp get_component_type(%Client{last_seen_user_agent: "Android" <> _rest}),
-    do: :android
-
-  defp get_component_type(%Client{actor: %Actor{type: :service_account}}), do: :headless
-
-  defp get_component_type(_), do: :gui
 end
diff --git a/elixir/apps/domain/lib/domain/version.ex b/elixir/apps/domain/lib/domain/version.ex
index c75a63e13..0e8d746a0 100644
--- a/elixir/apps/domain/lib/domain/version.ex
+++ b/elixir/apps/domain/lib/domain/version.ex
@@ -1,4 +1,9 @@
 defmodule Domain.Version do
+  alias Domain.{
+    Clients.Client,
+    ComponentVersions
+  }
+
   def fetch_version(user_agent) when is_binary(user_agent) do
     user_agent
     |> String.split(" ")
@@ -21,4 +26,15 @@ defmodule Domain.Version do
   def fetch_gateway_version(_user_agent) do
     {:error, :invalid_user_agent}
   end
+
+  # TODO: Remove once all clients are on versions that support resources changing sites.
+  # Connlib didn't support resources changing sites until https://github.com/firezone/firezone/pull/10604
+  def resource_cannot_change_sites_on_client?(%Client{last_seen_version: version} = client) do
+    case ComponentVersions.get_component_type(client) do
+      :apple -> Version.compare(version, "1.5.9") == :lt
+      :android -> Version.compare(version, "1.5.5") == :lt
+      :headless -> Version.compare(version, "1.5.5") == :lt
+      :gui -> Version.compare(version, "1.5.9") == :lt
+    end
+  end
 end
diff --git a/elixir/apps/domain/test/domain/version_test.exs b/elixir/apps/domain/test/domain/version_test.exs
index ecd2944d3..3ec60d5c8 100644
--- a/elixir/apps/domain/test/domain/version_test.exs
+++ b/elixir/apps/domain/test/domain/version_test.exs
@@ -1,7 +1,7 @@
 defmodule Domain.VersionTest do
   use ExUnit.Case, async: true
 
-  describe "fetch_version" do
+  describe "fetch_version/1" do
     test "can decode linux headless-client version" do
       assert Domain.Version.fetch_version("Fedora/42.0.0 headless-client/1.4.5 (arm64; 24.1.0)") ==
                {:ok, "1.4.5"}
@@ -39,4 +39,114 @@ defmodule Domain.VersionTest do
                {:ok, "1.4.5"}
     end
   end
+
+  describe "resource_cannot_change_sites_on_client?/1" do
+    test "apple client below version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.7",
+        last_seen_user_agent: "Mac OS X"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "apple client at version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.8",
+        last_seen_user_agent: "Mac OS X"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "apple client above version can change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.9",
+        last_seen_user_agent: "Mac OS X"
+      }
+
+      refute Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "android client below version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.3",
+        last_seen_user_agent: "Android"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "android client at version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.4",
+        last_seen_user_agent: "Android"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "android client above version can change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.5",
+        last_seen_user_agent: "Android"
+      }
+
+      refute Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "headless client below version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.3",
+        actor: %Domain.Actors.Actor{type: :service_account}
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "headless client at version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.4",
+        actor: %Domain.Actors.Actor{type: :service_account}
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "headless client above version can change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.5",
+        actor: %Domain.Actors.Actor{type: :service_account}
+      }
+
+      refute Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "gui client below version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.7",
+        last_seen_user_agent: "Windows"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "gui client at version cannot change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.8",
+        last_seen_user_agent: "Windows"
+      }
+
+      assert Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+
+    test "gui client above version can change sites" do
+      client = %Domain.Clients.Client{
+        last_seen_version: "1.5.9",
+        last_seen_user_agent: "Windows"
+      }
+
+      refute Domain.Version.resource_cannot_change_sites_on_client?(client)
+    end
+  end
 end