OK so you have a lemon… I would have thought you could have what I experienced, the loosening of the extruder gear from the extruder wheel but it would give you extreme underextrusion which does not show in your print.
Edit: I can’t really tell but enlarging your picture seems to show some, you may just be at the early phase of the extruder failing
When you did the belt tensionning, have you noticed if your belt was running at an angle to the pulleys? I hade this on mine and loosened both tensionners to fix, I moved the printhead all over the bed to balance the tension before tightening the 4 screws. My belts are now running almost perpendicular to the pulleys (I still have a very small angle). Just asking because on your screenshot it seems the bottom of the belt on the right is grey rather than black indicating it might run against the pulley flange (but that may be just an optical illusion).