Samsung flow won't work with my 9+ and new tab s4

[Saturnzoon]

I just got a new galaxy tab s4 and read that you can connect my 9+ mobile to the tablet via Samsung flow. I downloaded it to my 9+ as it didn't have the app, the s4 does have it, so when it installed it had to pictures screens and said to start the tablet and when it picks up my 9+ in the bluetooth search connect them, but the tablet doesn't pick up my 9+ and I don't know what I'm doing wrong as people told me they should show up in bluetooth.
Any suggestions would be great please, as I Cant find anything on you tube that helps either.