IntelliJ (and all other JetBrains IDEs) can be slow or buggy under Wayland. A workaround is to run your IDE with in X11 mode, which uses the compatibility layer offered by Wayland. More info here.
Meanwhile, if you still want to use the native Wayland mode (aka WLToolkit), you should know some things:
- The rendering currently runs in software-only mode, meaning all drawing happens on the CPU rather than the GPU. As a workaround, try enabling the Vulkan pipeline, which enables the GPU-accelerated rendering via the Vulkan pipeline. Go to Help > Edit Custom VM Options, and add
-Dsun.java2d.vulkan=true. - Smooth scrolling can suffer from current limitations. So, disable smooth scrolling can help: go to Settings > Editor > General, and uncheck Smooth scrolling.
- Code Vision has the same problem. Disable it by going to Settings > Editor > Inlay Hints > Code Vision, then uncheck everything.
- Finally, be aware of the current limitations of the native Wayland mode (with the Vulkan pipeline). It’s still under development. Everything is detailed here.