External storage mounted multiple times in different folders is shown only once

Expected behaviour

An external storage (in my case S3 Object Storage bucket) can be added multiple times to the Nextcloud configuration. I use this, to add one bucket twice: once as read-write and once as read-only using different folder names.

Nextcloud browser frontend and Android app show both folders correctly with the respective permissions. The iOS app should do the same.

Example: Mount S3 bucket test-bucket as folder Test 1 (read-write access) and as folder Test 1_read-only (read-only access). Both folders should be shown, each with the given permissions - like they do in the web frontend and the Android app.

Actual behaviour

iOS app shows only one folder per external storage.

Example: Only the folder Test 1_read-only is shown, but with full write access (which has been granted to the folder Test 1).

If the external storage is only mounted once, everything works correctly. This issues only applies to cases, when the same external storage (i.e. the same S3 bucket) is mounted twice.

Steps to reproduce

See above mentioned example.

iOS version

iOS 12.2

App version

Nextlcoud app 2.23.5

Server configuration

Nextcloud version: (see Nextcloud admin page)
Nextcloud 15.0.7

Start by reproducing the issue in the iOS app with the same S3 bucket mounted once read-write and once read-only under different folder names. Inspect the external-storage handling and compare the displayed folders and permissions with the web frontend and Android app; done means both mounts appear with their respective permissions.