Wi-fi only not working

I'm using wi-fi only option.
When wifi is disconnected OpenVPN show "pausing".
Is mobile data not suppose to work after that?

if wifi-only is selected, the app will connect *only* using wifi.

I understand that.
But what happens when wi-fi is lost?
I see that it says "pausing", but is it supposed to kill all data connections?

if seamless tunnel is set, all traffic will still go to OpenVPN, which will be dropped because there is no connection to the server.

That makes sense, thanks!