My new S25 Ultra doesn't go full screen

[usersU7AWXItQX]

This is the same problem I had with my S23 Ultra, when I watch YouTube, or other media like Rumble, ect... directly wired with hdmi to a monitor, the picture is using only about 75% of the screen on the monitor, and the screen on the phone is short on both ends. There's no full screen settings anywhere in this s25u, and it's getting very frustrating now, because there doesn't seem to be anyone at Samsung who has answers. 

The monitor is a newer Samsung curved gaming monitor, and when I put the phone in Dex mode, the screen is in perfect full screen, and when scrolling on YouTube, it also is full screen. When I try to watch a video, it goes into the above described smaller picture, with large borders around top, bottom and both sides. I would appreciate any help I can get on this, because this nice phone should be able to do this without me having to be an IT guy to make it happen.

[usersU7AWXItQX]

When I had the s23u, i always figured they would fix this with an update, but here we are, two years later and still same problem.

[Tidbitty]

Pinch it?
You either have to set it to fill screen or pinch it outward.

[usersU7AWXItQX]

There is no zoom to fill screen in settings, that's not an S25u , and pinching the screen does nothing.

[Tidbitty]

When I get home I will check my phone and see if it does not fill screen.

[usersU7AWXItQX]

Yeah, because your pictured phone settings don't exist on the S25 ultra.

[Tidbitty]

Interesting thing testing. I had 2 cables. One shows your symptoms and the other doesn't.

[usersU7AWXItQX]

That is interesting

[Ammo56]

On the phone when on landscape mode, pinch to zoom on the video and it will go full screen. Mine does

[usersU7AWXItQX]

It goes past full screen, and cuts off the top bottom and sides, and it doesn't fit right. And on the monitor, there's still a big gap with nothing on the top and bottom. Aparently the aspect ratio is NOT the same on both my monitor, and the phone, which is probably my main problem, and it will never fit right, no matter what i do. The phone aspect ratio is actually 19.5:9 not 16:9, and my monitor is 16:9. Dex fits perfectly though, which is still a mystery, but it looks like this will never fit correctly. It goes full screen on the phone, but the problem isn't about that, it doesn't fit the monitor. Thank you everyone for your responses, I really do appreciate your help. 👏 😊