REL Longbow 2.4 G interference?

My REL sub works wireless with a 2.4 signal or at least it use to.  There has been no change in location but now it works only if I touch the sub antenna just so or move the sub much nearer the transmitter.  I've turned off my 2.4 wifi at the router.  It's a condo so my neighbors could have a lot of signals bouncing around, I don't know.  

I would think not since REL doesn't have one but I have to ask - Is there a solution for this kind of situation (proprietary 2.4 channel antenna to antenna)?