When I render geometry caches or images, everything appears to be done in the background and any dialog is not shown.
How can I fix the issue?

I find this only happens if there is only a single image/frame being done. (which makes sense because there can't possibly be any feedback on a ‘single’ frame - other than it's being worked on)

Otherwise there should be a dialogue box - perhaps in your case it is just minimized.

In case of a single frame, although it can't tell the progress, you can see it in the task manager as mantra.exe

Thank you for your quick reply!
It works for me when I set the cache/render range over multiple frames as you said.