main reason for all to fail is bug instability you can either wait for next stable update or follow some advice and tips I could give you 1 use adaptive battery 2 use medium power save 3 prevent background apps from consuming data in battery device care 4 put unused apps to sleep 5 reduce some permissions given to apps that are not necessary for running of app 6 use dark mode 7 use location when necessary as in maps Google search or any location based app else constant use loads battery causing heating 8 prevent network inputs like NFC bluetooth WiFi from working together too many network inputs will cause heating and lagging 9 while charging keep phone idle 10 turn off auto sync use when necessary 11 reset phone settings once clear cache 12 if nothing works once try factory reset 13 use accubattery to know battery health 14 use glasswire to keep tab on app's using net data per hour and data speed live
I hope this helps because one ui bugs can be fixed by samsung when new updates come till then try these tips they could help to reduce battery heat up and loading so that smooth charging works and device runs smoothly
What's the price of s20 plus and ultra? It's way above 70k. See their forums and community, they are rotting with being buggy and constant overheating issues, not to mention that auto focus issue thou.