That Getting Hitched pic toilet bag looks like a boat keel. Maybe to keep the TV moving straight.
I poked around with a stick in there, after almost getting my arm stuck.

Redw and Rusty and Chris pegged it. What looks like a web sitting above the pipe is actually glue running down the pipe. That ain’t it.
But Chris and DGARRI are also right that the yellow area in the middle of the photo is a ridge just below the pipe leading down from the floor mount. Either a reducer or poorly aligned female adapter of the next section. In either case, between the ridge and the 22.5 angle bend, the paper probably catches on this ridge and starts a-jammin’.
Should be replumbed, I reckon. Too bad the last two guys who removed the toilet didn’t say anything.

Guess I be writing to Jack again for a warranty repair.
Thanks for all your help. And the picture too. Donations of or gift cards for extra toilet paper gladly accepted.