In the last couple of months I have noticed that after I take a shower that my bathroom smells like mildew. It does not smell however after someone takes a bath. I am in the process of remodeling this bathroom but I'm not sure if the smell is coming from the drain, behind the shower walls or what. I did accidentally drop a plastic razor cover down the drain and I'm not sure if that has blocked the drain. We have poured liquid plumber down the drain but it doesn't seem to help. I would appreciate any suggestions! Thank you!

Are the tub and shower separate units?

Does this shower has some kind of ventilation ?

I did accidentally drop a plastic razor cover down the drain and I'm not sure if that has blocked the drain. We have poured liquid plumber down the drain but it doesn't seem to help Are you complaining about the shower drain as well?
In order to help you must localize the smell. If this is coming from the walk in shower is it coming from the drain or some where else? Back to you, Tom