My S6 Edge finds my Roku 2 but not my Roku 3 . Why?

[AC Question]

My S6 Edge finds my Roku 2 but not my Roku 3 . Why not

I have a new Galaxy S6 Edge. I was streaming to my Roku 3 a few days ago and now when it searches for devices it only list my a Roku 2 which is in a back room. It never finds my a Roku 3

What can I check to correct this on my phone?
I've reset my a Roku and enabled mirroring.

Thanks