MK cartridge doenst fit

I just bought a set of refillable cartridges for the Epson 4900. Only the MK doesn’t fit (right compartiment, first one on the left). I can not push it deep enough to get a ‘click’.
With an original cartridge, no problems.

Any ideas ?

Please post photos of the cartridge. It’s very possible that the position tab (a removable piece near the front right of the cartridge) is partially out. These can shift during shipping.