I had the same issue, intermittent water and a “groaning” noise when no water (pump straining) came out. I knew water wasn’t frozen in the line inside the freezer door because I put a long 16” zip tie all the way up there, so I followed the path backwards and the issue was very simple in my case. The deflector that insulates the water lines inside the refrigerator from the vent that blows into the crisper drawer had become dislodged and the water in the water lines INSIDE the refrigerator was frozen.
I unplugged the fridge and used a hair dryer for about 5 mins to melt the frozen water inside the lines behind the crisper drawer and replaced the cover, making sure it snapped into place. Now water flows without issue.
I will update this post if any other issues develop, but thanks to John, and the rest of you, I have a clean ice cube flapper (tried that fix first) and water from my dispenser.
FWIW, I have both the fridge and freezer set to 5