I have found it is best to never travel with a full black tank and to always close the roof vents when heading out.
I did have a problem with sewer odors in the bedroom one time. My Miramar has washer/drier set up in the bedroom. I took everything from the closet and removed the panel on the back wall. That's when I discovered the stand pipe for the washer was missing its cap. When driving with full tanks from one camp site to the next it forced odor through that pipe.
I temporarily duct taped the pipe...problem solved.
Good luck on solving yours.
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