Where did the test take place and surely it penetrates more than 3 meters.
I doubt that they will disclose how far it can actually penetrate.
It’s best to keep pot belly in north korea, as well as the mullahs in iran guessing IF they’ll be safe.
this FAS article explains why 3 meters is useful for the B61-12:
https://fas.org/blogs/security/2016/01/b61-12_earth-penetration/