can you take a picture for the class to help you out? 
my guess it’s just good healthy soil(fungi are a main ingredient) and the gnats are feasting, coming in from anywhere. they smell mycorhizzae like flys love shit.
search OG for … oh hell:
and try the bT bacterial attack. stickytraps are mostly your monitor not your defense. however i have seen “sticky trap mulch” covering containers almost completely up to the stem, these seem like a waste unless your bread is on the line. 
