$sequence looping?

I have created a custom NPC animation that supposed to be looping. When I bring the sequence to Garry’s Mod, it doesn’t loop. It simply stop when animation ends.
I tried to put “loop” in qc command but it seems to not giving any effects, because loop has to be done in Faceposer. I’ve put loop point to the end so it would loop to the start frame, but in gmod the loop looks jittery.

So how do you looping sequence in proper way?