Classic Outlook Keeps "Not Responding" and freezing

-- Microsoft did another cumulative update including KB5074109

Do you mean KB 5078 127 ?

If so, I have seen some small number of users still having problems with Classic Outlook even after this update.

The only workaround I can suggest is to use the option that was suggested for fixing the original KB5074109 problem without uninstalling it:

Move your PST/OST files out of your OneDrive folder.

https://support.microsoft.com/en-us/office/how-to-remove-an-outlook-pst-data-file-from-onedrive-b6b9e522-59bd-40f7-949f-168d0aa9b38e

And then use ScanPST to check for errors.
https://support.microsoft.com/en-us/office/repair-outlook-data-files-pst-and-ost-25663bc3-11ec-4412-86c4-60458afc5253