Thanks for reporting. This is a regression in Slicer-4.11.20209030 that was fixed in https://github.com/Slicer/Slicer/commit/9aa9ed8b8aa06704ece1f0caa50d46cd7825ea4a.
Unfortunately, Slicer Preview Release is not functional yet (No images shown in slice viewers in latest preview release (Slicer-4.13.0)).