Yeah, it sounds like you have the cam of the dual-cam hitch mounted too far back from the coupler. Mine is 18" from the center of the coupler to the center of front bolt that fastens the cam bracket to the trailer tongue, and it never slips out. But hindsight tells me that 17" would be even better.
To check yours, go to a big empty parking lot and turn the rig as sharp as it will turn when going forward. Then stop with the trailer at the max turning angle, and get out and look at the end of the trunion bars in the cams. If one trunnion bar is nearly out of the cam, then you need to move the cam brackets an inch or two toward the coupler.
After you get the cam brackets moved, then check the lift up brackets too. The chain should be straight up and down between the cam and the lift-up bracket. If not, then move the lift-up bracket an inch or so towards the coupler too.
Brackets for propane tanks, battery, etc., might limit where the cam bracket and lift-up brackets can be located. If that's your problem, then you need to visit a good welding shop and have them move other stuff so the hitch components can be located exactly where they need to go. After the hitch is properly installed, then the propane tanks and battery can be located anywhere they will fit.
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 EcoBoost SuperCrew.