I was having an issue on Ubuntu 20.04 where anytime I would save a file to the desktop, the desktop would freeze for a few seconds, and all icons would disappear or reappear. This happened when dragging items to the Trash as well.
The journey to get the answer was not very direct, but in the end, here is what I did to fix it:
I am not sure if they had any effect or not. I do know that on the 5.10 kernel which comes with linux-oem-20.04, it did not help. On the 5.11 kernel, it also did not help. Not sure if the effect of running it helped on 5.6 or not.