Can't start Android app connection

Hi.

I’m new to all of this consept. So, please keep up on your mind, that I’m a newbie here.
Under normal circumstances, I use OpenVPN for Android all the time. When I decided to try Tailscale on my Android 10 device and also disconnected the OpenVPN for Android app, I still cannot connect with Tailscale app, because the switch will not stick there.
Can you help me on finding a solution to this?

Thanks.

My device is a Xiaomi Pocophone F1 running custom Evolution X ROM.

Yet found the solution. My OpenVPN for Android connection has its Always On switch on. So, removing it solved my issue.
Is this mentioned anywhere else?

I filed https://github.com/tailscale/tailscale/issues/1017 to make the Android app detect whether another VPN is running and give a useful error message.