Scapple hangs on closing document (beach ball)

I have had this problem for years. I have had it with about four different versions of MacOS and with at least four different Macs during this time and with every update of Scapple. I have not gotten any sort of satisfactory response from tech support. I use Scapple heavily and create several different documents in a workday – use them for freeform notes when reading client medical records and to draft versions of a diagnostic summary. Very often, when I try to close a document I get the beach ball freeze. The information in the document is autosaved and is always there on re-opening after a force quit. Either doing a for-safety’s sake save anyway or just trying to close the document by with clicking the red dot or CMD-W, I get the beach ball. The only solution in each case is to force-quit (and usually the force-quit window shows “Scapple is not responding”. This has generally seemed to occur at random intervals but recently it happens EVERY TIME I try to close a document. It does not matter how much information or formatting I may do in a document – any content at all or multiple notes with colored boxes etc, I am getting to the point where I may look for another software despite years of use of Scapple and loving it. The fact is that doing this force quit thing multiple times in a single session of client review notes is a massive PITA (this morning I’ve got seven Scapple docs to work in and it has happened EVERY TIME WITHOUT EXCEPTION that I’ve closed one of them. Any suggestions before I start a software hunt? I have never in decades of Mac use seen a problem like this in any software that has persisted for so long. Thanks.