How can you be so sure it's not front focusing as the bottle is round and there is nothing in front of the target (the "C"). It's possible that we're just seeing the tail end of the dof range. Anyway, I suppose this could be easily verified with live view + MF.
The halation in the f/1.4 shot sure makes it look like there is something wrong with the lens though.
Even though the bottle is square (as identified just now by the OP), you can see the f/1.4 shot shows purple LoCA in front and green LoCA in back with the middle area (the in-focus area) still soft. Anytime you have the red/purple LoCA on a shot, you are definitely not front-focusing. Front-focusing should yield a green glow around the focus-target, assuming the lens is not apochromatic.