Shower drain leaking

We just bought a house 3 weeks ago and have just inhabited the second floor with our children. When the three of them took a shower last night I had water dripping from the ceiling on the first floor. Upon inspecting the shower I found that when I took off the drain strainer that some silicone sealer was loose laying in the drain. After I pulled the silicone sealer out I found a very weird connection. It is a plastic formed shower and when you pull up the screen there's a 4 inch round white plastic fitting. In the hole of the fitting Loosely fitting is a 2 inch piece of Plastic drain pipe. So there's about a 32nd inch Gap between the pipe and the fitting/donut.

I am not in a position to remove the shower. What could I use to repair that Gap or fill it in?

You should not have to remove the shower. Being the shower is on the 2nd floor, your best bet is to open the ceiling below for access to replace the fitting.

If your looking for a quick fix, silicone it, AGAIN.
But honestly, How did that work out?

There is a lot of info buried here about shower drains.

Take a pic of the drain and post it please. A picture is worth a thousand words and then some.

Very curious what happens on this thread. I had a prospect call with a similar problem.