Can you please check whether in the Project settings you have checked the “Force export all images” checkbox? We will check this more in depth though, whether the numbers are considered image frame animations, which could also be the root cause the bug. Thanks for reporting this!
I’m not sure, but based on reading the above mentioned details, the imageset behaviour will probably need some refinements not to export any files whose name is ending with a number, just those that are part of a sequence. Maybe imagesets are exported even if the ‘don’t export’ checkbox is ticked, so they’re there when anything in the project needs them. Thanks for the feedback about this use-case.