ECCkeygen() produces localPublicKey->pmY->mNumDigits of 1 when expecting 12

[AWell.1]

We have an STM32F37II device in an older generation of a product that ECCkeygen() works as expected. But in a new version of the product, which uses the same MCU and cyrpto libraries, and which uses nearly identical firmware (it was ported from the older device), the ECCkeygen() function works for the localPublicKey X keys, but not for the Y keys. the pmY->mNumDigits comes out of ECCkeygen as 1 instead of 12 and that causes the Y keys to be mostly 0's. I believe that the arguments going into the function are correct. Our flow follows the ECC Key Generation flow chart (RNG init, ECC curve init, publicKey point init, privateKey point init, ECCkeygen). None of these return failing statuses.

Do you know why ECCkeygen would return the Y mNumDigits of 1 instead of 12?

Thanks in advance for your help.