Yes, there have been fixes related to this, thus the first step is to update to the latest release of MMW and MMA.

Yep, been happening to me for years. I posted before, got no help except "get the latest version"

https://www.mediamonkey.com/forum/viewtopic.php?f=26&t=85644&p=425872

Current release is 4.1.29: https://www.mediamonkey.com/forum/viewtopic.php?f=3&t=8811&sd=d Strongly suggest updating to it.

I believe I'm having the same issue. I'm syncing to my Android phone with the Windows app. I think this has started being a problem since updating to 4.1.28 from 4.1.26. Files will appear to be missing after the sync on the device. On closer inspection of what's on the SD card, blank .m3u files have been made for all the missing files (I guess this is something MMW does before syncing) but the actual music file hasn't been synced for some reason.

I think this only seems to be happening to certain files that have changed slightly - it only seems to delete things I've played recently (which I guess are things it needs to update the library played counter with.) Then, after syncing ~2 more times, it will eventually converge on putting all the files onto the device again. It's pretty weird.

Stats:
MMW 4.1.28.1905
Windows 10

MMA 1.4.0.0934
Android 10
Samsung Galaxy A50

I turned on confirm delete for the device, synced normally, played 5 or 6 songs and synced again and was asked to delete 400+ songs

This log: UGUGQGZLEJ

Cancelled that sync before it started and then synced again and it synced normal and my playlists reflect the song changes
this log
HLHSS6TK6D

MMW 4.1.29
MMA 0933
Android 9
Samsung Note 8

I've had this issue for a long time and did a wipe of all music and MMA for the last 2 beta's but its happening almost daily now.

I will sync during the day and MMA will delete 400 to 500 songs (it's always the same number and never over 500. Since my last reinstall it's been 487 ) and then redownload them. It used to happen every few weeks and I would just let it go but it's happening daily now.

If I cancel the sync and rescan, it will download the songs it deleted and update as usual. I don't see a pattern and it does the large number when I have 800 songs or 3000 songs on my phone. I usually have confirm deletes turned on to catch this but turned it off a few builds ago.

I sent log 8Q3335P4X2 with the detail Ignore (autocorrect did that)

And I posted this earlier about playlists not updating
https://www.mediamonkey.com/forum/viewtopic.php?f=21&t=97172

I let it delete about 100 songs and cancelled, did a rescan, synced and it downloaded the 100 songs. Not all of the playlists updated to reflect this but some did. I now have several playlists of "100" showine 80 to 99 songs.

I sent log 71QQH8HEBE after I have several syncs say everything is up to date..

Hi,
I tested on Moto G LTE 1st gen Android 5.1 using MMA 1.3.1 Official and MMW 4.1.18 Official without any issues. I would strongly suggest that you upgrade both versions and du a sync few times if needed till all made changes and fixes kick in and then report back in case of any issues.

Now both MMA and MMW have new releases out with many sync improvements in between them.

Start with updating MMW.

Sometime when I do a wireless sync, MMA will delete a large number of tracks (usually around 500 - often precisely 500), then re-download the same tracks in the same sync session. This makes syncing take much longer than it needs to - how do I make it stop?

I keep my entire library (5500 songs) on my phone's SD card, so it's not swapping out new material. And I haven't changed any sync settings (usually) when this happens. And it only happens, say, 1 in 5 times. Irregularly.

MMW 4.1.12.1798
Win10
MMA 1.2.0.0608, Pro
Moto G 3rd gen
Android 5.1.1

log YV8HS67L3X