Robohelp 2020.7.46 - Editing Image Maps not possible

I have a project with lots of topic using graphics with image maps to let user select area of interest. We're currently using latest 2020.7.46 release. After updating to this release I found that I cannot edit the existing image maps any more. The menu that is displayed after a right-click on the image does contain "Edit Image map.." option. For testing I already creaetd a totally new topic with an imgae and added a single imgae map area, connected to an existing topic. It was created correectly and works fine in browser preview, but no editing (moving or resizing map area with cursor) possible. When opening such an imgae map topic I also see an exclamation mark at imgae map section telling "<IMG> elements require an alt section that cannot be empty" Of course, I added this, but message stayed, even after saving and re-opening the file. Maybe someone has an idea.

Is anybody else out there using image maps at all ? In that respect, the new Robohelp HTML UI is a huge step back as compared to the legacy UI from 2019 or earlier. There, one could move or resize map areas using arrow buttons. This allowed exact placement. Now try this in new version (if it would work) using mouse cursor on a big screen with high resolution - almost impossible)