DIAGNOSIS A slow fill is almost always a water supply issue, not the washer itself. The inlet valves on the machine are fine, but they aren't getting enough water pressure or volume.
FIX Check your home's water supply first. 1) Make sure both the hot and cold water faucets behind the washer are turned on all the way. 2) Disconnect both fill hoses from the back of the washer. 3) Place the ends in a bucket and have someone briefly turn each faucet on. You should see strong, full streams. If one is a trickle, the problem is in that hose or the house's plumbing (like a clogged faucet screen). 4) Also check the inlet screens on the washer where the hoses connect. Use pliers to gently pull out the small circular filters and rinse them clean.
IF THAT DIDN'T WORK If water flow from the house is strong and the screens are clean, the inlet water valve on the washer itself could be failing. They have solenoids that can get weak over time, but this is less common than a simple supply blockage.
HEADS UP When you check the faucets, have that bucket ready—there will be water in the hoses. And when cleaning the inlet screens, be careful not to poke a hole in them; they're fine mesh. Just rinse, don't scrub.