OK. I think you have updated your iphone from IOS 13 to IOS 14.
There was an issue with IOS 14 (https://discussions.apple.com/thread/251829006?page=3).
This should be fixed with Linux kernel 5.10 (see https://github.com/potato1992/Iphone_usb_tethering_fix).
You should update your Linux if uname -a is lower than 5.10.
sudo apt update
sudo apt upgrade
I can't test this, because I don't have IOS 14.
There was an issue with IOS 14 (https://discussions.apple.com/thread/251829006?page=3).
This should be fixed with Linux kernel 5.10 (see https://github.com/potato1992/Iphone_usb_tethering_fix).
You should update your Linux if uname -a is lower than 5.10.
sudo apt update
sudo apt upgrade
I can't test this, because I don't have IOS 14.