I’m installing a new set of disc brake pads in these Ultegra brakes: exactly the same as the old pads. L03A. I’ve done this before with no problem. But this time, when I slide the pads in, they are pretty much up against each other - with no room for the rotor in between them. And no, I did not grab the brake handle while the wheel was off… And I have checked to ensure that the backing plates are completely separated, pushed as far outward as possible. Any ideas?