Did I screw up my liner?

I have a vinyl liner and went to clean behind my light. I suspected mustard algae was hiding back there so I removed it and vacuumed a ton of stuff out. The light was attached with metal screws to a plate in the wall. The liner was cut out around this hole. While I was cleaning I noticed the liner started getting wrinkled and floating! I quickly put the light back in but now there are sagging areas all around the pool - especially in the corners. I can tell there is water behind the liner.

Should I be concerned? Is there anything I can do to "fix" it? Was this a wrong way to clean behind the light? I'm hoping the water will just drain out eventually.

The liner still had some big wrinkles but it is going down. However, when we vacuum the hose seems to stick to some areas and is very hard to remove. I'm guessing it's because of the water behind the liner. Is there anything I can do except wait for the water to go down?

Also, I noticed my light now has a few inches of water in it - touching the bulb. No idea how that happened since I was very careful with the casing when we pulled it out. Should I replace the whole thing?

I would definitely get the light fixture out of the niche, drain it and dry it before the water get's to the electrical parts. Make sure the fixture is sealed well before replacing it.