What is going on with the S20???

Ugh..sorry for your issues. I know your pain! that's frustrating as it can be it's a simple fix - they have to replace your phone.

It's a Samsung problem. A lot of the s20s and note twenties had motherboard issues. I had all those issues plus more and once they replaced my phone I've had no issues but intermittent T-Mobile service problems. Samsung makes it very difficult though to get a new phone. I took it to an authorized repair facility and he's the one that first diagnosed the motherboard issue and denoted that it needs to be replaced (1500$ note 20 ultra I purchased directly from Samsung with the new watch). They still will not respect them and wanted me to mail in my phone for their technicians to look at it and we all know that just means they do a hard reset and send it back. And hardware issues don't go away until the hardware is fixed or replaced..other users with the same problem mentioned they had to send their devices to Samsung three different times for them to finally agree to replace a phone like it's their new protocol. This never used to be the situation with Samsung. They have always been so accommodating until recently. Being without a phone for over a month for me is unacceptable as well as many people since we use them for work and Samsung does not give loaner phones unless you have their insurance. I got lucky and the last day I could sign up for Samsung care plus, I canceled the insurance through T-Mobile (which is more expensive but has more coverage) and got Samsung care plus. However another rep did not agree with the first rep and told me that loaner phones are not issued understand Care Plus and of course I haven't had time to read the fine print. However, they did agree to send me a new phone after all. But it took much time and patience.

I wish you good luck on your journey!