iPadOS Files app can't open folders with 60+ files

I have been using NC for over a year now with iPadOS files integration.

It has been mentioned years ago here that the iOS iPadOS files app cannot open folders containing more than 500 files, however lately since iOS15 and the latest app updates I cannot open folders with more than about 50 images which has pretty much rendered the platform uesless and am having to use iCloud until a fix arrives.

The error states:
Content Unavailable
The folder could not be displayed because of an unknown error.
Try Again.

I have about 3000 images and I had separated them into folders of 150 files each and was getting by, but now that even folders of 60 images can’t load it’s over for me. iCloud for example can open a single folder containing 3000+ images without issue.

I have tried launching a new NC instance with all defaults for testing and loaded it with only 1 folder of 150 images and got the same result. It applies for all file types.

Again, this only affests iOS and iPadOS FILES app integration. The Nextcloud app has always has no problems in itself, but that’s no help because it’s uesless without a working files app integration.

Because thi sis happening in the files app and not the next cloud app, there is no logging what so ever to determine the problem. Logging only happens when using the NC app.

I got exactly the same problem. My Nextcloud-Account is provided by my employer and it was working pretty good on my iPad. I organize not really huge amounts of pdf-Files ( about 180 files of literature on one topic) in one folder. The last months it was runnning smoothly but after the last update to iOS 15.6.1 this folder can’t be opened and I get the same statement. I copied one half of the files (about 80 files) to another folder. This seemed to work, but after one or two following attempts of opening the folder, the same error message occured.
For me Nextcloud is getting unseless, too, if there is no app integration. In my case I want to open the files in a pdf-reader app (LiquidText) which is not possible without integration.
Does anybody know how to fix this?