JDKs installed with SDKMAN are not selectable in the IntelliJ IDE
For me both of of the below helped to resolved.
- Invalidate cache (File > Invalidate Caches / Restart)
- Update the IntelliJ version to 2021.x (This would solve much of ur problem!)
Use File > Invalidate Caches / Restart option which should invalidate local caches. Hopefully it's a glitch in the dialog cache.