A/C shuts off after an hour of driving

The A/C stops working if the weather is hot after about an hour or two. This does not happen if I just let the car run in the garage (tried that already so I could take it to the mechanic in my city instead of having to be out of town to get this fixed.) It also doesn't happen if the weather is cooler, it has to be a sunny day.

The blower is still working, I can hear it just fine. But nothing is coming out of the vents. I think from various research the condenser may be icing up. I've seen solutions ranging from A/C pressure switch, drain tube clog, water in the system, blocked coil. Where would you start or do you have a different suggestion altogether?

Also, maybe a separate issue or maybe not; the driver side vent nearest the window will always blow normal (non A/C air) or even hot air as soon as the A/C fails. It works normally up until then. The other vents at least feel like there is cold air barely coming out when the A/C has failed.

So this is perhaps a blend door actuator problem on top of everything? Is this the main issue causing everything? Or just a side effect that will go away once the A/C problem is fixed? Thank you.