Have a client on QB 2022 ProPlus with this same issue
she is trying to fix 300+ transactions in MULTIPLE files and it takes roughly 45 seconds PER edit

This is abysmal - 

Before the Technicians start to give me the same lame "fixes"  Yes I updated, YES I restarted YES I verified (found and fixed data damage)   Yes I have rebooted the computer MULTIPLE times
there are no direct solutions I can find OTHER THAN  closing and reopenin quickbooks the moment it slows down.

Abysmal is the best word for this

My GUESS is that there is a conflicting background process but I do not have the time to dig