Hello! Recently I updated my Xiaomi phone to MIUI 12.5.5 (Android version: 11 RP1A.200720.011) and I <<think>> this is when my phone started acting weird. Most of the times when someone calls me, instead I get a text a text message from my Carrier (COSMOTE) that I had a phone call. When others call me it usually says that I am busy or my phone is turned off. Yesterday however my mother called me, it rang, and after I picked up, 5 seconds later my best friend called me and rang aswell, so I had 2 phone calls at the same time and it worked fine, I don't understand that's possible. I tried disabling Wi-Fi calling and VoLTE but no luck. Today I decided to reset my phone to factory settings, but it does the same thing. I called from my mother's phone, the first one worked, the second did not. Then my dad tried calling twice, it rang normally. Then my sister called, it did not rang (It said phone is probably turned off). I did not move my phone at all during these tests, and I have 5 bars. What can I do?