Something very strange is happening: I have vault #1 which contains two text files and a password protected dmg file. Everything worked fine until today when I opened vault #1 and the dmg is no longer visible. Nothing has changed in this vault so it can’t have been deleted. If I look in /Volumes/XYZ I can only see the two text files.
I also have vault #2 which is backup of #1 and on Google Drive - this backup is months old as neither #1 or #2 has changed recently - they are essentially read only. I open vault #2 and the dmg isn’t visible either, this vault was last accessed in November last year.
This has to be a problem with Cryptomater/MacOS. I upgraded to the latest version and the problem still happens. At one point I did briefly see a third file in the mounted volume but it was too quick to make out before it disappeared. I wonder if Cryptomater is adding the dmg file then removing it immediately.