Very slow work with smart objects

I experience significant slow performance for about 1-2 months, especially when working with smart objects, but also when saving files. Often PS freezes and I have to wait a lot of time to be able to continue. Saving in the background while continuing to work as I was able to do before, is also impossible.

A really big change for the time needed to save a file, even it takes a lot of time first to start saving the file after the command is initiated so I can start seeing the percent going from 1% and on, while in this period all is frozen.

Opening and saving a smart object, or converting a simple layer into a smart object also takes a lot of time. Overall I feel that PS is significantly not performing as before,

I thought that I am working with too large files with many smart objects and layers at the beginning, but I experience it even in files with a few smart objects and mid-size resolutions like 1500 x 2500 for example.

I tried many different options like changing scratch disk files, different PS versions, verifying I work with 8-bit/channel images, RAM is set to use 78% (from 64 GB total).

I do not see any other performance issue with the PC or with other software.

Is someone able to resolve a similar issue?