Hi @illEez Certainly advisable to wipe cache partition after updates. May be an idea to reset all settings if Network Reset does not fix matters. General Management-Reset-Reset All Settings
If that does not fix issue Go to Settings- Connections - Wi-Fi - Tap the cog symbol to the right of your router - Forget . This is the bottom right on the list. Toggle your Wi-Fi off and on again - Select your router from the list of available connections, and run through all the connection steps.
Thereafter go to Settings - Connections - Wi-Fi - Tap the cog next to your router on my device and choose More and select the MAC Address Type,set this to Phone MAC. If the issue persists, I would suggest pressing the Volume Down and Power buttons together for around 10 seconds until the phone restarts, the reason being that this will refresh the software and address any issues that might be causing problems. An idea also to reboot the router if wifi issue not solved.
Should there still be an issue with Mobile connection when out and about may need to restart device / reinsert sim or reset your APN settings.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.