I reported it as a bug here because I realized that this strange behavior also happens when I try to reject incoming calls normally, via the UI, and not just programmatically. When I get an incoming call and press the red handset icon to reject it, everything looks as if the call got rejected, but the actual connection (with waiting tone) continues on the calling phone and after a few seconds it starts ringing again and the Phone app with incoming call screen pops up again. Only pressing the red handset button the second time hangs up the call.
Someone in the other thread reported that he tested it on a 10 II and couldn’t reproduce such problem. So maybe it’s XA2 unique (maybe something to do with its specific modem). Or maybe my system is broken (which would be strange as I flashed it less than a month ago and didn’t really mess with it too much).
It would be great if more people could test it, especially on XA2.
To test it, just please call to yourself from some other phone and reject the call the normal way via the UI, i.e. using the “red handset” icon/button of the Phone app UI. Please repeat a few times and see if the call always gets rejected correctly.
I’ve got an application to reject calls in a quite advanced state (with configurable white list, black list, etc.) so quite soon I could share it if this problem could be ironed out.