either you have closed the wrong valve, the valve is faulty, or the water is getting in some other way.

Do you have a very high water table around your pool? I have seen pools overfill from water entering through the hydrostatic valve.

Don't know what your setup is, but mine has a floating plastic ball under the plastic cover in the well. You need to adjust it much like the ball in your toilet tank. It takes a little tinkering to get it right. The mechanism might be stuck and you should check this out. Suggest you lower pool level to desired point then check to see if water is filling into the pool. It is is lower the ball until the water shuts off. You may have to go back and adjust again.

This is why I rarely post in this forum anymore.
The OP asks for help, receives a reply within 90 minutes, another the following day, and doesn't have the courtesy to come back and tell us what the problem/solution was.
Maybe it's petty on my part but I find it annoying.

This is why I rarely post in this forum anymore.

So, cascade, where do you do most of your posting?

I post more frequently in forums relating to my hobby: 2 stroke motorcycles. Why? What does that have to do with anything.

My point was that at one time I posted here quite a bit. As a pool builder with 20 years experience in the industry I was happy to offer some bits of advice. At the time it seemed that there were more owner-builders asking technical questions on this forum. Now it seems most posters seems to ask for builder referrals, complain about the service they are getting, ask about tile or plaster choices or just post photos. There is nothing wrong with that, I just don't feel the need to respond.
I still check in here occasionally and will post in response to a technical question. Perhaps its foolish of me to expect some response from the person asking the question. In this case I don't even know if the OP read the answers he got.

We had the same issue with the system and ended up replacing it with the LevelSmart Wireless Autofill System, and it’s been a great solution.

It keeps the water level just right without me having to constantly check or top it off.

https://www.konalabs.com/products/levelsmart-wireless-autofill