Miramar shower leak

Once you make a claim under warranty it doesn't matter if it runs out, your good until it's fixed. Sounds like it's coming from the shower drain except if it were leaking right at the drain you should see water right away. It's possible that it is leaking at the drain very slowly then running on the bottom side of the shower floor and then dripping down which is taking a few minutes to show up. Water leaks can be a real puzzle but remember water always takes the easiest route. If the gray tank is directly underneath there would not be a very long run of pipe but there still needs to be a trap so there will be some length of pipe but the water wouldn't sit in the pipe for any length of time. There should be access to the trap but who knows. If not the only sure way to fix it is take the shower out and they won't want to do that so now it comes down to who gives in first. Stay with it until it's fixed.