Honestly, I think you should use the time to try to discover what's happening.

I think the odds are your installer did something wrong, but that is by no means certain. And if the problem doesn't originate with him, it could reoccur when a new liner is installed!

For example, you might have a pool brush that had -- somehow -- a stray stainless steel bristle installed among the nylon. Mostly, it would work OK, but occasionally it might penetrate the liner.

I know that's improbable . . . but improbable things happen everywhere, every day!

Good luck!