You could check the
error.log (see FAQ) file. Not sure if it'll say anything though. Especially if you can "successfully" perform move operations, where "successfully" means FileBot doesn't show an error because FileBot thinks everything is OK because that's the status FileBot gets back from the OS.

Note that Finder is special. Finder can do things that other applications can't do. Especially when app sandboxing is involved too. Testing with other tools
(not made by Apple) from inside / outside the Mac App Store and see how they fare.

My best guess is that the issue is within macOS, because of some behavior in GoCrypFs drive is just slightly different from the other more common well-tested file default system implementations. At the very least, I doubt that it's something that can be fixed within the FileBot code base.