How can I connect Redmi K20 Pro back to my PC?

Solution 1:

first thing you should do is pick the yellow exclamation, check which .inf file is assigned and delete this file from windows/inf directory

pick the yellow exclamation und uninstall drivers

disable windows driver signature enforcement and reboot

double check phone settings, maybe switch to PTP and then back to MTP mode, let windows reinstall drivers itself

if MTP drivers doesn't install automatically,wpdmtp.inf is missing. install Windows Media Feature Pack