Phylacteral link with twinned boss

Hi,

I don't know if this is intended or an oversight but when the Crystal Ore boss is twinned it becomes impossible to do any damage to any of them because of 2 instances of phylacteral link. Both marked monsters protect each other.

Thank you.

Also just had this happen.
Crystal Ore map with Twinned bosses.

After killing the first trio, the second trio became invulnerable.