Screenshots Uploading at low resolution?

Between Upload not saving screenshots and Upload Studio just plain not working, I've got a very low opinion of the One.

Xbox services are currently under heavy load from tall the people playing Starfield on cloud, screenshot uploads are a very low priority task. Upload servers are nowhere near as numerous as download, basically you queue to upload

The Xbox servers are constantly load balancing, and the last few weeks with all the people playing Starfield on cloud has been an adventure in load

With gamepass app it works well but the quality of graphic very low. This screenshot from ROG Phone 2

Have you tried booting into low resolution mode? Maybe something was changed and is ot compatible with the change setting. Low resolution mode basically reset your display settings to the lowest settings. To do this you press and hold the Xbox button and
the Eject button until you hear a beep to turn on the console. Note This will boot your console in a low resolution mode.

These are nice download and upload speed. Cloud gaming should run fine on your phone. Is this a 5Ghz wireless connection, right?

Usually the gaming experience on mobiles are not as good as on PC or console because of the mobile screen resolution. The image would not be as good as a device that has a higher screen resolution. But you should not experience low framerates.

Are you able to test it on another phone to see how it goes?