Cannot upload pictures to album after upgrade to 28.0.3

[sanctimon]

Describe the bug
Up to 28.0.1, when accessing an album, there were two options: "Add photos" or "upload photos". These options have now disappeared and been replaced with a "New" button. When clicking this button, a Windows Explorer button pops up allowing to select files from the local machine. There is no option to add photos already on Nextcloud. When selecting files to upload, nothing happens. The File explorer window closes and no files are uploaded. No log entries are created.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Photos',
2. Click on 'Albums'
3. Select an album previously created.
4. Click '+ New'. No option to select existing pictures or upload new ones.
5. Windows Explorer window pops up. Select pictures to upload.
6. Nothing happens. No pictures are uploaded or added to the album.
7. Checking in the 'photos' folder to see whether the pictures were uploaded does not show the newly selected pictures. Preview of the Photos folder is broken upon scrolling down.

Expected behavior
Option to add existing pictures to Album should be available. Option to upload new pictures to album should add pictures to album.

Screenshots
No screenshots provided to protect data.

Desktop (please complete the following information):

• OS: Windows
• Browser Edge
• Version 28.0.3

Browser log

-moz-user-select' is not supported by Chrome, Chrome Android, Edge, Safari, Safari on iOS. Add 'user-select' to support Chrome 54+, Chrome Android 54+, Edge 79+. Add '-webkit-user-select' to support Safari 3+, Safari on iOS 3+.

-ms-filter' is not supported by Chrome, Chrome Android. Add 'filter' to support Chrome 53+, Chrome Android 53+.

A 'cache-control' header is missing or empty.