A couple of days ago suddenly my Windows File Explorer became slow, files did not get sorted, and icons were lost. I also felt Logos is slower.
I found advice by googling. In my case it was stopping and restarting Windows Search Indexer.
After it had finished indexing (took 12 hours), I felt that Logos and some other programs have good speed.
Those who feel that Logos is slow, it might be good to check that all relevant files are indexed. I am not sure will Windows index everything by default in a new computer.
One can check in the Control Panel, under Indexing options that the disk with Logos files is indexed.