otb 20+ 5G VERIZON stuck on 10

[watertraveler]

I love the s20 plus - last phone with sd card. My old one died so just got a new phone in a Verizon black box used smart switch - up and running EXCEPT on Android 10 / ui 2.1 Google play 2019 old as sin. Software update tries to dl update 5. It downloads then asks to install , when I do it says checking for latest update then error 405.

I'm guessing because its no.longer supported that I can't? Obviously I want to be past ver 10 / ui2.1 so I assume I need to flash with Odin.

Haven't flashed anything - need help

 

[watertraveler]

Running software version
G986usqu1atfg

Yes want to keep Verizon for vvmail and WiFi calling. Just went through unlocked phone nightmare

 

[Laura Knotek]

What is OTB?

 

[watertraveler]

So my smart sync from Samsung downloaded on laptop said it was updated. Deleted and got from Microsoft... Then I was allowed to sync and upgrade via pc / cord to 11 then it's but each firmware update had to be done via pc/ cord. To next version or UI.

Afterhours of downloads and resets at 13 and 5.1. hope this helps anyone else in this situation