AsNoriuanswered grow question 3 years ago Even if it is mycorrhizae , means soil got huge humidity boost at certain time and became super microbial active, could be too rich and burn seedling.
I never had any fungus on any soil brand, tried a lot !!!
Ask for refund , I would.
Even if they call me idiot, I would not risk investing time for n potential thread ...
All the Best !