E1600306551484 , via OnePlus 8 T-Mobile , Sep 21, 2020 : Since getting the 10.5.20.IN55CB update, I basically cannot make any outgoing phone calls. The VoLTE and VoWIFI will not work and those features had to be disabled by the carrier. According to Sprint/T Mobile's website, a fix is not expected until 9/26/2020. That will be 3 weeks of a phone that doesn't work properly. https://community.sprint.com/t5/Dev...Does-Not-Reliably-Dial-Out-after/ta-p/1083415 OnePlus's customer service is a joke. My calls got disconnected 4 times before I got through to someone who I thought would help. I told her the problems and asked if my phone could be down graded to a previous firmware. She told me it was possible but I'd have to respond to an email from her with my personal information to get the process started. After giving my full name, address and email...I received a return email saying that a down grade was not possible and have since been bombarded with spam email on that account. I bought Samsung flagship phones for years before deciding to try OnePlus and truly regret the decision. The problem with the update and subsequent interactions with customer service leave me feeling like I've been scammed. There is nothing that will be done to help with this problem until OnePlus decides to fix their software and I just wanted to let other users know this is a known problem now and the customers are getting screwed.