Generally about low success with evocation

Long time I’m trying to evoke demons to help me in professional field.

Interesting case was with Bifrons, he offered a little help this winter but I missed opportunity. Then he stopped answering me.

I know, demon can show the way, demon can provide coincidence.

But too many times demon just don’t appear. Even when I do evocation in lucid dream if demon “don’t like” me, he will not appear.