Not really enough information. Is this a lacto only ferment, or done with sacc. How long has it been, and what are you seeing.
677 is heterofermentative (produces both lactic acid and alcohol). If fermented on it's own, will have some small kraeusen. Not all lacto works like this.
If added after, or with sacc, it may create a white thin pellicle. It may also do nothing, as alcohol will hinder it's ability to reproduce.
Hops are bad for it. Generally lacto prefers to work in wort where there are zero hops. It may do nothing if you have hops in the wort/beer.