Media PC Help

I'm turning my old PC in a strictly Media pc. It works, but the problem is I can only get one folder on my storage drive to show up on DLNA on Chromecast with TV. I've tried making other folders and they never show up. Anything I put inside this one folder will show up.. For the life of me, I can't figure out how I got this folder to work.

I've even tried on my new PC, and the same folder with all the same permissions.. Doesn't show.. If I put files on my OS drive into Video's, they show up..

I've tried asking Chat GPT, and that got me nothing bust wasted time, with it repeating the same bad advice, or suggesting Plex.. I have tried Plex, and it see's all the folders, but doesn't alway see the files inside the folder. Maybe it's a setting I need to play around with, or I need to rename the files ?

Suggestions ?