Pre-wash water filling when function is not selected

My friend gave me an old LG WM2032HW washing machine because it was not filling with water properly (slow or not at all).

I purchased a level switch, cleaned the inlet valves and hoses, and that problem seemed to be resolved.

No error codes were ever observed.

Unfortunately, now that the water is flowing normally again, I see that water from the pre-wash hose fills the machine even when the function is not selected (I had it on hot/cold, no pre-wash).

By the time the hot water kicks in, the machine is already overfilled with "pre-wash cold water."

My friend says this was not happening before.

So, not only the pre-wash cold water hose is letting water in when it shouldn't, but also the machine is not telling it to stop when the machine is overfilled.

I tested both inlet valves with a multimeter and, electrically, they are working properly.

Any ideas on what I need to do next?

Thank you!