This same issue is happening to me. 2023 with a little over 2k miles on it. Sometimes the air blows strong out of all vents. Sometimes it’s weak and the drivers side vent is much weaker than the middle. And sometimes it feels like there’s no air flow what so ever even on speed 7 even though I can hear the fan kicked all the way up.
Cycling through the air flow modes doesn’t fix it.
Turning the hvac off and back on doesn’t fix it.
Cycling auto mode doesn’t fix it.
Only thing that fixes it is turning the truck off and letting it sit for a bit.
The quality in these gen3’s is embarrassingly awful. I had 2 previous gen2’s that were flawless.