My shower drain started leaking about 2 months ago. In order to fix the leak I had to replace the trap and riser and drain. It worked for about 2 weeks and started leaking again from the drain. I used plumbers putty and the gasket was on the underside of the shower stall. I did it again the same way, and again in another week it was leaking. What am I doing wrong??

My shower drain started leaking about 2 months ago. In order to fix the leak i had to replace the trap and riser and drain. It worked for about 2 weeks and started leaking again from the drain. I used plumbers putty and the gasket was on the underside of the shower stall. I did it again the same way, and again in another week it was leaking. What am I doing wrong???
What type of shower do you have? Custom tile or plastic/fiber glass floor and enclosure?
If a plastic/fiber glass floor and enclosure does the shower floor "give and flex" a bit when you step onto it? Let me know, Tom

It is plastic/fiberglass and it doesn't seem to flex at all. Maybe it does and I just cannot tell it does