Game Clips Uploading to Xbox Live but not showing up there

I've been having this issue as well since the December 1, 2020 update, and it's not limited to game clips. Screenshots are affected too.

I'm having the same problem on the One S. First i thought of giving it some memory space and deleted one clip. The clip would not delete. today it shows up as a thumbnail-less clip that can't be played. I can't upload any videos, the xbox tells me it's uploading
and it tells me the clip has been uploaded to live, but when i check theres nothing there. On the mobile App I get the notification that a clip has been uploaded and I can view the clip on my phone, but if I try to share or save the clip it says a problem
occurred. As soon as I leave the clip page, it disappears from the captures tab on the app. The clip I deleted on my xbox doesn't show up on my Mobile App, thats a good thing.

Hey there, perhaps the clips not showing have not been uploaded to Xbox Live.

https://support.xbox.com/en-US/xbox-one/apps/upload-studio-managing-clips

Do that to see if they're uploaded.

Have you checked you are looking on your Xbox rather than on Xbox live? As the default is uploaded clips on Xbox live it wont show clips that you havent uploaded till you use the drop down menu

If there are problems with xbox live with too many people online it can sometimes cause problems with sending message, achievements unlocking or in your case problems with gamer clips. I had problems with gamer clips recently as well. Two of my clips
recorded and uploaded but they were in low video quality and didn't have any sound. Another time I made a clip but it wasn't showing up in my recent captures list. Then a day or two later a notification popped up saying my clip was uploaded to xbox live.