You have a leak. Fix that first.

Yes, the liner is pulling away because water is escaping somewhere. Plug the leak, then the liner will usually settle back on its own. If it doesn’t, you can coax it.

Most pools have a slow leak at a seam, a return fitting, or the skimmer. Find it using a dye test or by looking for air bubbles. Patch it with a vinyl patch kit – the ones with glue are fine for small holes. For bigger tears, you want a submersible patch or a pool repair tape.

Once the leak is fixed, refill the pool slowly. The water pressure will push the liner back against the wall. If it doesn’t, you can use a shop vac on the skimmer to create suction and pull the liner tight while you fill. That trick works for stubborn liners.

I wouldn’t mess with weights or clips. They’re band-aids. Fix the leak, and the liner will behave.