SOLVED: New videos not able to be played on TV, ok via laptop

[acoustics]

Having fixed the issue of Jellyfin refusing connection, all was good for a few days. I managed to upload files to my NAS and watched them on my TV. However, new videos I uploaded could not be played back on my TV, though I can access them through my laptop. This shows that there is nothing wrong with the video files. No settings have been changed, yet newly uploaded files cannot be viewed. I have checked for updates for Jellyfin, ffmpeg via the Asustor app store. Everything is up-to-date. Any suggestions on how to fix this sudden issue?
Thanks!