no upload at all of automatic photo upload

Sorry there will be many problems in one

Expected behaviour

the auto upload should be smooth with a lot of checks after each file creation and each file upload and should be slow to give the system the ability to adapt.
If there is already a file named like that a copy should be put in place or the file should be queued at the end of this transfer queue to give the user the ability to choose what to do.

Actual behaviour

no upload or progress at all if I try to continue the upload of my entire library which wasn't finished in the same folder.
No upload at all if I try to reset the app and don't move the folder created by the app on the server to another subfolder named backup for example.
I've reset the app 2 times already, so this is totally reproductible. I'm trying a third time by moving the subfolders created to another subfolder. Now the transfert is actually happening. There are for now, no more 404 errors, sign that the folder are created and verified correctly now by the app.

The app crashed after 300 uploads on 13600 files to upload in total. I relaunched it and it continues to upload.

Steps to reproduce

Reasoning or why should it be changed/implemented?

an app not giving enough different error messages, can't inform the user of any problem or can't get people give the incentive to debug it themselves. Nextcloud is a hand made solution which requires a lot of debugging, so the more "if" the more "catch error" there are, the better.

iOS version

13.5.1

App version

3.0.2.16

Server configuration

Operating system:
yunohost debian
Web server:
nginx yunohost
Database:
Type : mysql
Version : 10.1.45
PHP version:

Version : 7.3.20

Limite de mémoire : 512 MB

Temps d’exécution maximal : 3600

Taille de téléversement maximale : 10 GB

Nextcloud version: (see Nextcloud admin page)
18.0.5 which is the last

The report names no source file, test, or entry point and provides no concrete reproduction steps. Start by reproducing automatic photo-upload continuation after an app reset on the stated iOS and app versions; done should include resumed uploads with progress and actionable errors instead of silently stopping.