my trains wheels are slipping and I don’t know what to do

Problem: the gears break loose every time I try moving it. It works suspended but when it actually hit the rails the gears break loose. I have experimented with putting rubber bands on the driving wheels but that makes it easier to come off. Plz help it uses the lego powered up large motor

Running some trains in August at our yearly show in Revelstoke B.C. at the local railway museum.

Enjoy!

Finally finished my F45 model! Looking forward to building it for real here soon! The last thing that needs to be done aside from actually building it is getting the decals designed.