ssgi4in12

Hello everyone. My chairot is a 2002 Awd. I recently did a complete air-conditioning work: changed the compressor, condenser and evaporator. Blows cool air too.

I stay in a place the outside temperature gets up to 34 degrees Celsius I had to set the air conditioning temperature on the lowest.

But I recently noticed that after the ac is on and cooling for about 15 - 20 minutes, the amount of air is greatly reduced and it brings out a kind of mist from the vents. If I switch the ac off and powers it after about 5 minutes it blows right amount of cool air and does the same thing after few minutes.

I contacted an ac mechanic, he tells me there is a kinda thermostat on the evaporator and that it could have failed. And that it could be forming ice or so.
​​​​​​
Can someone help out with possible causes?

Thank you.