Clean the flange well or use a new one and install over the drain and new wood.
Floor creaks under toilet.
Normally this is avoided if when the wood subfloor underlayment is installed it is glued and screwed so there isn t any movement or chance for there.
A laminate floor in a friend s house seems to be possessed overnight gaps appear in the floor where one piece butts up against another.
Remove enough of the drywall to open the area under the shower and toilet.
You may not think of your floor as vulnerable but in the bathroom it is.
A spongy floor around the toilet is a strong indication that the subfloor has absorbed water.
Peel back the flooring around the fixture and you will.
You may need to scrape the flange with a small putty knife and use a wire brush to get it clean and free of any corrosion or debris.
With some effort you can slide them back tight again.
Place a bucket directly under the soft spot and open a small hole using a keyhole saw.
How to fix a rotten floor around the toilet.
Around the toilet the floor may get flooded from overflowing.
Repair floor under toilet nail the plywood to the floor joists.
Make sure to make your nails flush with the wood.
Answer answer the fact that there is a squeak under the tile suggests that the wood underlayment subfloor is moving to some degree.
I doubt that it is the tile assembly itself moving independent of the floor but that would have to be verified.