Some Videos not playing inside nextcloud (also happening on

Hey guys. So ive just realized that I can stream videos from within the cloud. However im facing some issues with that. some files play, others dont and weirdly enough the logs stay empty. The web-logs as well as the actual logs on the raspberry. This issue also happens on the page with the same videos. some load, some dont. They are normal .mp4 files and even if I upload & then download them again they work fine on a normal player so it has to be a nextcloud issue. Since theres no logs I dont really know what to give you guys.

Nextcloud version: 21.0.3
Operating system: doubt any of this matters since it also happens on the demo cloud but its raspbian
Apache version: 2.4.38
PHP version; 7.3

I guess I can share one of the videos that dont play on my cloud & the demo-cloud. Maybe someone can analyze it and tell me whats wrong.

Something is wrong with the MP4 container in this file…

If you just open the file in something like mkvtoolnix and re-encode the file into MKV container (leaving both, audio and video components as-is), the resulting file plays fine in the browser…

thanks. solved it for all the files that didnt work