I have had a couple of instances of this since updating to V3.7.0 on Win7, never before the update.
I have a program that implements source control by storing files in an XML database. I wrote it about 20 years ago! It creates files, deletes then and renames them, etc and logs all its actions. Twice it has renamed a file and it has disappeared from my local drive, so it complains it can’t open it again when it tries to read it.
Insync Feed shows the file has been renamed. Google drive activity shows the file has been renamed as well and I can see the file in my Google drive but it is missing from my local file system. However, while investigating it suddenly reappears without any logged activity. In the last case over an hour elapsed between me noticing it being missing and it reappearing and the file was renamed about an hour before that. Totally bizarre.