Thanks for info.
I gathered debug file yesterday and today but I don't know how to get them from RPi4.
No I didn't enable 4K60. I didn't change anything in config. Just installed software, installed Confluence skin - to match other player for comparo, set resolution to 2160/24 and then to 1080p/60 and 1080p/24 when tried to play movies.
Today, following your advice, I set white list for 1080p/4k 23.976/24/59.97/60 and set "adjust refresh" to start/stop.
After setting resolution to 1080p/60 I could play 1080p movie for several minutes without freezing. The same after setting refresh rate to 23.98 and 24 fps.
Then I changed resolution to 2160p/24 and still could play this movie with only one freeze, but later played well for several minutes without any problem.
UHD movies are different story. I tried "3:10 to Yuma" and "Murder in orient express" and both movies were played with hiccups and audio was ahead ~2 seconds. Movie freeze from time to time.
I can send you debug log if you tell me how to retrieve it.
My Best
ZW