AC really cold, for a while the beginning with far right passenger vents, warm air begins blowing

My AC blows cold, really cold, for a while the beginning with far right passenger vents, warm air begins blowing. The warm air eventually blows in center vents and then left side (driver) vents.

Assuming my refrigerant level is correct. Can you think of something that would cause this and is there a way I can test it?

My car does not have a cabin filter. Not sure if this may be related but sometimes the vents can have a slightly mildew smell. In the past, I have sprayed disinfectant (Lysol) into the outside vent near the windshied wipers with fan on.