Text (markdown) with link to file cannot be opened

### Steps to reproduce
1. Create a new Textfile via nexcloud 20 webif (text.md).
2. Enter some Text, mark it and add a link to a file (new feature on nextcloud 20).
3. Open that file (text.md) on nextcloud android.
4. File will not open (opening takes forever).

### Expected behaviour
- Text file should just open and be shown.

### Actual behaviour
- Opening text file takes forever.

### Environment data
Android version: Android 10.1

Device model: Huawei Mate20pro

Stock or customized system: Stock EMUI 10

Nextcloud app version: 3.14 RC1

Nextcloud server version: 20.1

Reverse proxy: YES (NGINX)