There are thousands of Iota converters installed in RV's. If this is a generic problem, we would have heard about it. You're not the only one living in a hot area.
My first Iota was defective. It would boost charge for only 15 minutes. I contacted them and they sent me a new converter.
The spec says the converter must be operational at 104F. Have you verified with thermometer when it quits? It's defective if it quits at or below 104F. If it quits above 104 then we can't call it defective. In this case, you should be able to change the temperature setpoint. Ask Iota what mod can be made to make it operational for your environment. It's probably just a resistor change.
You could also go with the 'damn the torpedoes, full speed ahead' mentality and just disable the temp shutdown function.