Did they hook that toilet up to the tank, or is it just dumping out on top of the tank and sitting there? The vent was not hooked up! I would run water into that toilet and have someone outside to make sure that water does not start coming out from the edges of the underside cover! I feel blessed that all of my issues have been minor ones, but the vent cap that I finally found in the bedroom slide closet, that was loose and letting in black tank odor was Interesting..... Hold the phone, look for a removeable piece of wall covering around the bathroom. If you find an inspection cover, take it off and see if there is a vacuum vent behind it, sort of a screw in cap with air holes in it.. Mine was behind an inspection cover in the closet in the piping for the washer drain line, and was barely started in the pipe, allowing the odors to escape, happy hunting.
2015 Dynamax Trilogy 38RL, 2014 Ram 3500 DRW Maxtow package.