[BUG] strange behaviour when trying to get in sync with the instance

[mmattel]

Steps to reproduce

I dont know how to reproduce, it just occured after apdating the files via desktop sync. The files existed before updating and were marked to be offline available, then this happened (see video). Even if the files were no longer be offline available in the app, they can be seen and opened opened via the browser normally. When closing the app (wipe) and restarting, watching the oC and ws log, nothing pops up… The files cant be opened in the app, changing directory and reenter ect does not help. Rebooting the devices did not help, removed and readded the instance from the app with no change. Move the files to the root of the mount (smb) via the browser and the files were accessible ab the app. Moved the files up into the subfolder again and the problem reoccurred. I have created an app debug log (22MB) and can provide this together with the pdf file, but if possible to a safe location.

Update: I have recreated the pdf from Word (save as pdf as before). In the browser there is no change and it works as before but now the app can sync and view it - strange. I have kept the „problematic“ pdf as file to be able to reproduce the issue.

Expected behavior

Sync data

Actual behavior

See video. Occurs on iPhone and on iPad. Closing the app does not help

https://user-images.githubusercontent.com/3321281/120061753-eb2d3780-c05e-11eb-99b7-62178ed9dc12.mov

Client

iOS version: 14.6

ownCloud app version: 11.6.0 build 194

Device model: iPhone SE 2020 and iPad (same IOS version)

Server configuration

Web server: nginx

Database: mariadb

PHP version: 7.4

ownCloud version: 10.7

Storage backend (external storage): smb, gd

Logs

Web server error log

Nothing relevant found

ownCloud log (data/owncloud.log)

Nothing relevant found

@michaelstingl @hosy fyi