Maestral re-downloads existing Dropbox files on initial sync, creates some conflicts, and may be zeroing files

[claresloggett]

Describe the bug
After stopping and removing the official Dropbox client, and installing Maestral, using the same directory, Maestral appears to be re-downloading all the existing files. In case it could be a factor, note that I had selective sync enabled when using the official Dropbox client, although I made a careful effort when I set up Maestral to select the same folders for selective sync.

In addition, all the files in my top-level Dropbox directory appear to have been deleted locally - it currently contains only subdirectories, no files. I can still see those files in the Dropbox web interface, so I am assuming they would be re-downloaded and would reappear when the sync finishes. I am unsure though as I've stopped the sync (see context below).

I can also see some local conflicted-copy files, dated today. So it appears that Maestral has considered my local files to be conflicts with the files in Dropbox, even though there were no local changes to them. These conflicted files appear to be zero bytes.

Most alarmingly, I can see some files in the same directories which do NOT have conflicted copies but where the original files are now zero bytes.

To Reproduce
Sync some folders locally using the official Dropbox client. Remove the official Dropbox client. Install Maestral and configure it to use the existing local directory. Select the same folders for selective sync.

Expected behaviour
I would expect that any Dropbox files that already exist locally and have no changes would be left untouched, neither deleted nor re-downloaded, and no conflicted copies created.

System:

• Maestral version: 1.9.4
• Python version: Base OS python is 3.9.6, but not sure this is relevant?
• OS: MacOS Sonoma 14.6.1
• Desktop environment:
• PyQt version (for Linux GUI): I am on MacOS and don't think I have PyQt installed

Additional context
I'm new to Maestral and tentatively putting this in as a bug as it doesn't seem like expected behaviour, and the deleted/zeroed files are very alarming. Please tell me if I'm doing something wrong.

All my files on the Dropbox servers seem to be intact thus far, and the local conflicted copies have not yet appeared on the server. Maestral seemed to be creating successively more local zero-byte conflicted files the longer I ran it, so I paused the sync. I didn't stop the daemon, but maestral activity, which previously showed activity, now says "Maestral daemon is not running" - is this expected, or has it crashed?

I'm reluctant to restart Maestral without knowing what's going on, as my server files are still intact and I can still recover with relatively little pain.

[claresloggett]

Also, just to bring your attention to it, there is a comment from last week on a closed issue, reporting that zero-byte files are still ending up in Drobox - not sure if this is related to what I'm seeing. #925 (comment)