With headset, no ringtones

With my headset attached, ringtone is not working, neither on outer speaker nor on earphones. After answering the call, I can hear just fine. Ringtone volume is set to high value. Anybody experiencing the same on FP2? Is there a way to solve this?
I am using HONOR earphones (model AM12, Huawei) which work really fine (remote control & mic are good). I tried also another headset with the same result.

I can reproduce the problem. No active notification on incoming calls (or messages) with plugged headphones. However passive notification takes place by suddenly muted music. This is actually why I didn’t even try to find a workaround till now. But indeed it is a problem if headphones are plugged but not used in the current situation.

The same occurs with my FP1. Is it an Android issue, of a FP one?