Mold in shower drain

I have a strong moldy smell from a shower drain in a newly built house. I have cleaned the drain multiple times with baking soda and vinegar, bleach, drano, and the moldy smell is returning. The plumber came out and all they did is fish out a tiny amount of hair from the p-trap but that did not change anything (there was no problems with slow drainage, but very strong smell). I took a look in the drain and I saw that there is quite a bit of what appears excess gray ABS glue, and there...

Mold in shower drain