Saw the exact same. Tubi app on Shield = 4K HDR10; on Apple TV 4K (2021 and 2022) = SDR / resolution unknown, though it looked very similar to the Shield pixel resolution and quality. However, since the game is natively mastered at FHD SDR and only upscaled to UHD HDR, hard to know what the resolution truly is (my suspicion is that Apple TV was capped to FHD).
On Channels, I only ever saw it cap out at FHD SDR. I wouldn't be surprised if the FHD SDR profile cap was due to a client issue, where the UHD profile was only available with the verified native android client, thus it couldn't be parsed in a third-party client.
The following were the profiles available (to me at least):
ā Video --vid=1 (h264 1280x720 59.9401 fps 10168 kbps)
ā Video --vid=2 (h264 1280x720 59.9401 fps 8163 kbps)
ā Video --vid=3 (h264 960x540 29.97 fps 3817 kbps)
ā Video --vid=4 (h264 852x480 29.97 fps 1874 kbps)
ā Video --vid=5 (h264 640x360 29.97 fps 871 kbps)
ā Video --vid=6 (h264 480x270 29.97 fps 453 kbps)
ā Video --vid=7 (h264 1920x1080 59.9401 fps 14346 kbps)
ā Audio --aid=1 --alang=eng (aac 10168 kbps)
ā Audio --aid=2 --alang=eng (aac 8163 kbps)
ā Audio --aid=3 --alang=eng (aac 3817 kbps)
ā Audio --aid=4 --alang=eng (aac 1874 kbps)
ā Audio --aid=5 --alang=eng (aac 871 kbps)
ā Audio --aid=6 --alang=eng (aac 2ch 48000 Hz 453 kbps)
ā Audio --aid=7 --alang=eng (aac 14346 kbps)
ā Video --vid=1 (h264 1280x720 59.9401 fps 10168 kbps)
ā Video --vid=2 (h264 1280x720 59.9401 fps 8163 kbps)
ā Video --vid=3 (h264 960x540 29.97 fps 3817 kbps)
ā Video --vid=4 (h264 852x480 29.97 fps 1874 kbps)
ā Video --vid=5 (h264 640x360 29.97 fps 871 kbps)
ā Video --vid=6 (h264 480x270 29.97 fps 453 kbps)
ā Video --vid=7 (h264 [High] 1920x1080 59.9401 fps 14346 kbps)
ā Audio --aid=1 --alang=eng (aac 10168 kbps)
ā Audio --aid=2 --alang=eng (aac 8163 kbps)
ā Audio --aid=3 --alang=eng (aac 3817 kbps)
ā Audio --aid=4 --alang=eng (aac 1874 kbps)
ā Audio --aid=5 --alang=eng (aac 871 kbps)
ā Audio --aid=6 --alang=eng (aac 2ch 48000 Hz 453 kbps)
ā Audio --aid=7 --alang=eng (aac [LC] 2ch 14346 kbps)
ā Subs --sid=1 (eia_608 14346 kbps) [default]