MCU problems installing klipper on S1 pro

[LifeOfBrian]

Ok that sounds better.
Please check this post on another thread:

SKR 1.4 klipper NO MCU FOUND!

Check if Debian Bullseye Bug causing Klipper to no longer find the printer board - #8 is applicable to your case. If above does not help, then follow How-To Trouble-Shoot and post the dmesg.txt file