Missing documents

I’m really puzzled. I use LO on my macbook pro, 2015. Lately, I’ve had a few crashes with LO, leading to the autorecovery function on reopening. Just today, though, I find that for the second time in the last couple months a document is simply gone. No record of it at all. This time even, the previous version of the document is missing. The previously saved version is also gone. In fact all versions of the document, which had been saved separately under different names are gone. They are not in the Trash, nor anywhere that the computer finder is willing to show me. I even searched for all .odg files in case I had named it something different than I remembered. Nothing. It’s been a few weeks since I last opened the files, before Christmas, I certainly didn’t delete them myself and the Trash is full of other things that I haven’t emptied from before I even created the Draw docs in question.
What the hell is going on? Anyway to tell? (It’s never happened before, I’ve used LO for years), but all files were for the same client, one .ods, the others .odg. The folder the files were in is still there with other unmolested files.
How might I recover them? I presume the data is there somewhere, but the computer forgot the name or something like how files are “deleted” but still there. I already looked in the “recovery” folder in Library, but there’s nothing.
I looked in the Temp folder Library>Application Support>LibreOffice>4>User>Temp and found something promising, but either I’m doing it wrong, or the files aren’t relevant as they all seem empty. I duplicated the files and changed the extensions to .odg and opened them. See the picture. One was recognizably something I created at that time, but not useful and basically just a copy of a template with no additional data.

Version: 7.5.0.3 (X86_64) / LibreOffice Community
Build ID: c21113d003cd3efa8c53188764377a8272d9d6de
CPU threads: 8; OS: Mac OS X 10.14.6; UI render: default; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded

Do you use a cloud services? Some cloud services make files online-only after a couple of weeks. Doing that while the file is open is likely to cause a crash.
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Might be worth giving LibreOffice full disk access. If you had already then remove it and give it again.