The silenced phone still get phone calls / UI didn't change phone icon

Happens to me too. Phone is silenced, still getting calls.

Not even adult mod can silence it and it has a feature that mutes the phone & prevents using it.

UI shows the phone icon with the little lines left & right when silenced but Im looking at a call right now. Got the call sign while I was on another sim, switched sims, phone rang while muted, clicked on the phone, usual accept or decline icons popped up, clicked on accept and... well... See for yourself:

As you can (barely) see. Phone is on silence but the call still came through.