This may not be new to this PR, but on my Galaxy S23 running Android 14, I see the below problem.
Turn on Tailscale
Connect to VPN
Stop Tailscale (don't disconnect, just stop the app, for example using "Force Quit"). This way, the next time you start Tailscale it'll automatically connect to VPN.
Make sure you've enabled our Quick Settings tile
Start Tailscale
See that Tailscale automatically connects to Tailnet
-Look at Quick Settings tile and see that styling and text indicate it is disconnected
See Percy's comment in https://github.com/tailscale/tailscale-android/pull/357#issuecomment-2083325738: