Shower Drain Very Slow To Drain

[Upsdrew]

I have a 2019 Salem Grand Villa 42 DL. In the past couple of weeks the shower drain has been very slow to drain. I have used a snake, enzyme drain cleaner and baking soda and vinegar to try and fix the problem. Nothing has worked. I was told it could be a clogged vent. My question is, if that is the case, where is the vent. Someone also said something about a vacuum breaker but than someone else said that is only for the black tank. Any help would be appreciated.

[SeaDog]

vent stacks for the gray or black tanks terminate on the roof. Sometimes these caps can become blocked. It wouldn't hurt to ensure the vent stacks are clear.