iOS photos hangs with large sync queue

[vielleicht]

Steps to reproduce

1. Configure automatic upload of images in the app (disabled background upload)
2. Disable the iCloud-photo sync
3. Take pictures and create a long queue (20 is too less, 100 is working) without opening Nextcloud App and therefore prevent uploading
4. Pictures in photos app appear blurry, live images do not get shown. When trying to share an image (mail, app) an dialog “processing…” or “downloading from iCloud appears, but no progress.

Expected behaviour

missing sync to Nextcloud should not interfere with the system functions (like sharing Fotos with Mail app or social media app…), but it does.

Actual behaviour

It seems iOS is waiting for the sync to become ready, but the pictures are still available on the phone storage.

Screenshots

After opening the app, sync starts and after completion all errors were gone. If the problem comes back again, I will post screenshots

Reasoning or why should it be changed/implemented?

unexpected behaviour with major impact on the whole iOS.

Environment data

iOS version: iOS 15.1.1

Nextcloud iOS app version: Nextcloud Liquid for iOS 4.2.0.5

Server operating system: Arch.

Web server: nginx

Database: Postgres

PHP version: don’t know

Nextcloud version: 21.0.1

[vielleicht]

When the “queue is full”, sharing a new photo (maybe at the end of the queue) takes endless with this “preparing…” screen.

[vielleicht]

Additionally, when writing an email, adding an picture and sending it, iOS tells something about “waiting for download”. This is something I can’t explain, because iCloud is deactivated, so iOS should be waiting for Nextcloud. What is the sync mechanism Nextcloud app is using?