A possibility is that the water valve is clogged, not shutting off completely and allowing a tiny bit of water (a drop or two) to pass through every few seconds or minute or whatever timeframe is involved. Said bit of water builds up in the tube, held there by surface tension, where it freezes.

Either that, or you just can't set the freezer at maximum now, for whatever reason.

Water valve on my unit went to seeping, this situation built-up over a couple/three days time.

Move the freezer up a couple degrees.

the line runs inside/near the insulation for the freezer for some distance to get to the freezer door.

If the freezer is set low enough the water line freezes up.

it is common to many brands of refrigerators with through the door water on the freezer side.

I've inspected the visible freezer area area and there is no sign of a leak or ice buildup like in the pic posted. When I defrosted the freezer I would have noticed all that ice melting. I'm pretty sure it is just the water line that is freezing.

If the problem can't be fixed I think I'd rather not have water from the fridge than ice cream that isn't really solid.

I run my freezer at -2ðF (lowest setting available is -6ðF) and ice cream is nicely firm. Try reducing your setting one increment (available range is 1 to 9?) every couple/few days to determine what is the lowest that's workable without freezing the line.

Or maybe you've already done that ...

Otherwise, as you say, you'll have to make a choice.