Hi!
I've installed iOS 14.5.1 on my iPhone 8 plus and since then, I lost the signal and I don't have data. I have an Android phone, and my sim card works well with it.
I tried many things like:
Turn off/on cellular data
Turn off/on airplane mode
Turn off/on roaming
Hard reboot
Soft reboot
Reset network setting
Reset all settings
Erase all contents and settings
...
Same issues
Do you have any idea how to fix it?