Bottom freezer gasket completely came off the door liner. I pushed the gasket back in but its still loose and if I give it a slight pull it comes off again. I noticed that the liner edge slightly separates from the door very easily. Is the door liner broken and can it be replaced? or the gasket needs to be replaced?
Here are your parts
Parts for Whirlpool W8TXNWFWQ01 Refrigerator - AppliancePartsPros.com
The freezer gasket is item 14 in section 02.
Click on the correct color gasket picture or description you need and a new page will open with more info, views and a video.
You may find the video helpful.
You cannot just replace the door liner, you would have to buy a new door.
I cannot say what the problem is but it looks like they may have redesigned the gasket so a new one may fix the problem.
Put some silicone cement on the door liner channel, close the door and let it dry for a few hours, should fix the problem and save money.