Issue with synchronization: Names of files changed, others disappear

We’re having an issue with the NC accounts of two colleagues who, in addition to their work iPads, also use personal Apple devices — all connected to Nextcloud. When they upload files, the uploads usually appear, but sometimes they don’t. The bigger problem, however, is that file names are sometimes automatically changed into random strings like SKLdoE28dR — so completely unreadable that you can’t even recognize them anymore.

We initially suspected that it might be related to special characters in file names, but that turned out not to be the case — it also happens with very simple titles. Apparently, there are also cases where files can no longer be deleted, as if user permissions might be affected.

Does anyone have an idea what could be causing this?

Kind redards

These files were always created through devices using the ios-app? Or also the macOS desktop client?

Can you “follow” the files via webserver logs? The moment they were created, renamed, … etc. just to know if they were already uploaded under this cryptic name, if the same client changed it to this, or a different process?

Hi, thank you very much for your answer.

If I remember it well, I saw it appearing suddenly with another name while they were working on their iPads but I don’t know if their Mac at home was online at the same time. I can try if I can manage to reproduce the issue. Weblogs are a bit tricky because we’ve got about 1000 users, but we can try … Or is there a helper program that allows you to follow the logs on an iPad like you can do it in a Browser using the F12 console?

For long logs, that can be a bit tricky and you need to grep through… either a good specific filename, the user’s ip, …

e.g. when I create a file in the web-interface (textfile) and then rename it:

2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "POST /ocs/v2.php/apps/files/api/v1/templates/create HTTP/2.0" 200 229 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "GET /apps/files/api/v1/views HTTP/2.0" 200 121 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "PROPFIND /remote.php/dav/files/user/folder/sysyplo/sysplot.md HTTP/2.0" 207 726 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "GET /apps/text/js/ViewerComponent-ClBcMzJy.chunk.mjs HTTP/2.0" 200 1383 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "GET /apps/text/js/PlainTextReader-BaOW1zLc.chunk.mjs HTTP/2.0" 200 416 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "GET /apps/text/js/MarkdownContentEditor-Bx3yx86y.chunk.mjs HTTP/2.0" 200 4584 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:52 +0200] nextcloud.example.org "PROPFIND /remote.php/dav/files/user/folder/sysyplo/sysplot.md HTTP/2.0" 207 726 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:13:53 +0200] nextcloud.example.org "PROPFIND /remote.php/dav/files/user/folder/sysyplo/sysplot.md HTTP/2.0" 207 719 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"
2001:0DB8::11 - - [22/Oct/2025:10:17:42 +0200] nextcloud.example.org "MOVE /remote.php/dav/files/user/folder/sysyplo/sysplot.md HTTP/2.0" 201 0 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0" "-"

For such purposes it can be good to have a small test setup with less traffic. You can easily cross-check, add/disable apps, test new versions, test apps, try to reproduce problems without touching the productive setup.