LG Studio Refrigerator Water Tastes Terrible

We recently moved to a new house and purchased a LG Studio French Door Refrigerator SRFB27S3, both the water and ice taste terrible, like chemicals. The water is not drinkable and the ice ruins whatever drink you put it in. We've had the refrigerator for two months and I've tried everything, hoping someone has something new to try. Here's the situation:

  1. The water straight out of our faucets tastes good, that's what we're currently drinking. It's city water, not well. We don't have a water softener or whole home filtration.
  2. We have flushed at least 20 gallons through the fridge over the past two months. If you flush water through the fridge, it starts to taste better. Then once it's been sitting for several hours, the bad taste comes back.
  3. I contacted LG support, and they sent a replacement filter. The new filter did not help. Running the fridge without a filter doesn't help either.
  4. We also purchased a new waterline kit (warners stellian r-310 ice maker waterline kit) with the fridge and our plumbing is PEX.
  5. I've tried twisting the filter really hard (based on similar posts) and it seems to be in all the way in. When I remove the filter there's water in it, so I think it's getting filtered.

If anyone has other advice or input, it would really be appreciated. I spent a lot on this fridge and I'm so frustrated that the water and ice are unusable.