Pairing the IPhone with a Samnsung Sound Bar

My Iphone cannot pair with a samsung soundbar. When I switch the bluetooth in the phone the list of available and previously paired devices appears, but the sound bar quickly shows in the screen and rapidly move down the list and dissapear. How can I fix this? I've tried all the basic tricks: Rebooting the IPhone while previously switched off the bluetooth, same but previously in airplane mode on, reseting the network settings. I don´t want to reset the phone. I think is not a solution. Any help?

My intuition tells me that the problem is with the sound bar that cannot "forget" the iphone, but I have rebooted the Sound Bar to initial conditions and also nothing.