After a lot of other problems I have a new one.
My Soundbar is connected with my Samsung TV with an high quality optical cable.
I have set Auto Power link so the Soundbar switches on together with my TV, sofar so good.
But when I switch the TV off with his remote, and then the Soundbar with his remote, (or the other way around), after approx 20 seconds the TV remote gives the Soundbar a signal and switches on again! So then I have to switch to soundbar off a second time with his remote.
I have done a reset, an init, but as soon I use the Auto Power Link then this problem comes back again.
Have you followed the 'Connecting using an Optical Cable' and 'Auto Power Link' instructions on pages 10 and 11 of the user manual? Have a look here.
Also, it may be worth checking that the software on your Soundbar and Speakers are up to date. This link shows you how.
Let us know how you get on.