This might be a module issue rather than an engine issue. Using 3.1 beta 6.
The V40K module has screentips that appear when you hover the cursor over pieces on the map. It works at all zoom levels up to 100% but doesn’t work when zoomed in further than that (the screentips simply fail to appear).
I’m assuming you’re referring to the mouse-over stack viewer feature which zooms up all the pieces in a location by holding the mouse over it. That’s an edited feature so my guess is that the original designer set it to only operate at less than 1:1 zoom.
OK will report it over at the module boards. Did 3.0 have zoom levels greater than 100%?
If my memory serves me correctly, the 100+ zoom appeared in 3.1.