Why'd my ac fan blow on high but no cold air came out

Sounds like an air flow issue, yeah? Like cold air, but not enough? Until you shut it off and then turned it back on? If this is what you mean, it sounds like the evaporator core may be icing up -- from getting too cold and having too much condensation in the area causing ice. Ice is impossible to blow air through -- so air flow would be heard but only a little bit felt. Icing up is typically caused by an electrical issue not monitoring air conditioning performance properly -- such as with a cycling switch concern, where the switch keeps the compressor coil and clutch engaged too long. This is merely a guess and one possibility, but one I've seen before -- not necessarily with a Lexus, but on cars in general.