New tile shower drain has slight leak
We purchased a house in Va. That is new but has been sitting empty for 2 yrs... the upstairs bathroom shower stalls have a nice tile floor (small tiles) and larger tiles on the side. The master shower has a slight leak that we found after the third shower of the morning. There was a slight drip from the frame of the downstairs closet that let us know there was a problem. It stopped once the shower was shut off. I pulled the grating off and there is a plastic round fitting (~ 4 " dia.) that appears to be grouted into place as I could not lift it out and did not try to force it since did not want to damage the tile floor. I can see down to the PVC drain pipe and P-trap but there is a space between the plastic fitting and the PVC pipe that may be the source of the leak. I'm thinking I may be able to apply silicone to the joint space all the way around and fix the problem without having to remove the round plastic drain fitting. Any thoughts or suggestions would be greatly appreciated. I thought about trying to slide a cylinder piece down in there and glue it in place but did not know if that would be the best fix for this problem.
Thanks,