I am working with RoboHelp 2015. I have a legacy project for chm help and there are images in the topics with hyperlinks to other topics. The links are displayed in auto-sizing popups.
In one project, everything works just fine. When you click the hotspot, the popup opens adjacent to the image.
After generating the output (chm help), when I click an image hotspot, the popup opens at the top left of the topic pane. Actually, the popups suppose to open adjacent to the image.
Interestingly, the popup location issue relates only to popups called by image maps. If there are other links to popup topics in the text, they behave as expected.
Sorry, but about all I can suggest is to report it as a bug to Adobe and hope for the best but expect nothing to come of it.
I don't say "expect nothing to come of it" in any effort to disparage the Adobe developers. It's just that CHM is an old format and I'm not sure any real development has happened for years with RoboHelp or any other authoring tool to make things better for CHM format. Just the nature of the beast.