Coolant leak that can’t be found and destroys the engine.,

2018 Pacifica , we took it in for a recall issue, the day after it was loosing coolant and constantly overheating.. half gallon of coolant every three days or it over heated.. cannot find the leak.. we took it to 2 different dealers, they only can fix the result .. $ 5000 to replace engine parts.. but never coukd find what caused the issue in the first place.. Except , we took it in for a recall item.. 87,000 miles without problems, the day after the recall- it began. So I’m driving now, just got it back from the dealer- they say they found no leak.. so why was the coolent burning up so much and why was it in the engine, and why did my engine seem to fart out over night after Recall work.. It’s fishy to say the least.. my family owns 5 of these same vehicles.. mine is the only 2018… and the only one that had the recall work? anybody know what has happened to my Pacifica?? The first dealership said it needed a new radiator because it had a hole, the second dealer said the radiator was fine , but engine was ruined from Driving while over heating .. we never did.. once light was on.. they said coolant was in engine.. the other dealer said something different.. my trust is going down the toilet with my local Chrysler dealerships.. I just want to solve this fishy mystery.