BUG - Background Select dialog box next goes away

My question is where to report irritating bugs? I have the latest (non-beta) version of ManyCam ( running on the lastest version (again, non-Beta) of macOS. I have an issue where sometimes, after selecting a custom background for greenscreen (which does work fine), A copy of the popup window for selecting the image file stays there forever, unless I quit and restart ManyCam. As I am not on Webcam meetings almost all day, this is extremely irritating. I presume it’s a bug, but if not 1) is there anyway to fix it or 2) where do I report bugs?