I bought the Note 20 ultra last week and I am not receiving calls and my text messages are delayed. I only know I missed a call because I get the voicemail after the fact or people text me. This isn't helpful since I'm writing from home. I called customer service to troubleshoot: restart, reset, turn wifi on/off. Issue is not resolved. When I try to place a call it says that the network is unavailable or there is silence/no connection.
I went to the T-mobile store and they switched my sim card, but it did not resolve the issue.
