Mystery overheating 2005 (Honda Odyssey)

Hey everyone so i have a very weird overheating issue that is causing a lot of confusion, For context our car is on the island of jamaica to which the local mechanics aren't trained well and seem to be stumped. They thought it was the head gasket to which i firmly said i doubt it was considering there was no milky coolant nor white exhaust smoke. After two different mechanics we changed the head gasket and nothing was solved. so were back at square one.

The vehicle is idling regularly without overheating, driving more than 10 minutes the needle begins to climb and if not turned off will hit the boiling marker. We didnt watch it once and the vehicle did overheat to where the coolant began dripping on the ground. to which we decided the vehicle isn't operable and try to get it fixed.

1. Fans work, if we turn on the ac you can immediately here the two fans on both sides sound like a tornado.

2. Radiator has been pulled and inspected fully clean no signs of blockage within it.

3. Thermostat has been replaced with genuine OEM honda thermostat less than 2 years old Due to this being a vacation vehicle we drive it less tan 10,000 miles per year

4. Waterpump was also replaced with the thermostat and less than 2 years old Due to this being a vacation vehicle we drive it less tan 10,000 miles per year

The vehicle starts right up with no signs of struggle or virtually any issues. What is perplexing is the car went for a car wash and soon after began overheating. We did notice that someone took our radiator cap (likely because it looked new) and we put a new one back on. We're also not going to that hand wash anyhow. Any help would be appreciated