CISA key won't go in lock on a JMA blank but looks 90% identical

[NYKeys]

Could have sworn I'd had this years ago and swapping to another manufacturer's blank fixed it. Anyone know?

Using JMA CI-26

The two blanks are not 100% identical but are really close. Is there a better blank?

 

Thanks

[grahamparker]

That key is part of a master system so possibly on a slightly different blank than the standard Astral/Astral S.

Have you tried using genuine blanks ? It's all we use on these.

https://www.aldridgesecurity.co.uk/cisa-0005-cisa-00620-01-0-astral-astral-s-blank.html