I tried this in different duels and the result is the same: The effect of sangan and witch of black forest doesn't activate more than 2 times per turn, this means if I use black hole and have 2 sangans and one wotbf in my side of field, just two of then has the effect activated.
Eerie Code
If you're using the post-errata versions, their effects (as in, the effects of cards with their name) can only be used once per turn, so they're actually working as they should.