Maybe do you experience general slowdown with Idea, too?
For example when I open a Kotlin file in the project tree, it takes 3-4 seconds to open (even for a very small file).
Currently I'm using 2023.3.4 UE on Ubuntu 22.04.4 LTS (but I had the same problem with 2023.3.3 as well).
And my PC is not bad: AMD Ryzen 9 5900X + 64 GB RAM + etc.
IDE heap size is set to 8 GB, build and Gradle heap sizes to 4 GB - so it is probably not a memory/GC problem.
Any ideas? Thanks.