Can you capture 4K through the Xbox series s capture?

Why are you wanting to capture at 4K? the Xbox One S doesnt render any game at 4k, so all you will be doing is capturing an upscaled image.

Good day,

maybe because the 4K captures takes a lot of memory, try to minimize the capture duration through capture settings and make sure that your captures storage is not full then try again.

I am using xbox series s, i see in the box it says it supports 4k gaming, so this means it will not support 4k recording but will support 4k gaming display. I am able to play games in 4k but not able to record them.

I am not using any capture card for recordings

Your resolution may be the reason it's working. I run my Xbox Series S at 1440p and have capture stuttering like many people in this thread. Maybe the video compression works just fine if you're running your Xbox at 4k.

IGN does have a really good walk through on how to make sure your 4k capture is set up, but perhaps have a look at the different saving locations? it could possibly be saving to another destination that you're unaware of. But also, be aware, that 4k videos,
even SDR and 30 seconds long, can be larger than you'd expect.

capture 4k on xbox one x

The capturing was a problem for a while on the one dashboard, so hopefully its fixed for you now.