Upgrading Horns while cracked

[Former user]

If you upgrade the horns mutation while it is cracked, you can end up with more AV than you should. I just upgraded to the mutation to level 16 while my horns were cracked, and now they're giving me 7 AV even though the mutation description says it should be 6. As a side note, all horns have the same description, including casque.