Im wondering if E2E does not work, or if I am doing something wrong

I set up a fresh install of nextcloud 16.0.8 and enabled server side encryption and end to end encryption modules.

I created a user and logged in using the nextcloud android app(version 3.9.2 from FDroid).

I cleared out the default files and folders and created a new folder ‘Test’. I then set that folder as encrypted and got the 12 word key. I moved into the folder and tried to upload a file, only to have the upload fail. Saying “Null unknown error /Test” .

Am I doing something wrong? Or is this because end to end just doesnt work yet?