I should add, I'm using a pair of Samsung M3s (WAM350) both updated to the latest software via the Multiroom app and the latest software on the tv too.
Recently purchased the above tv and have had Multiroom speakers for a while. Internat signal has always been patchy but I now have a wifi extender + another hub set to repeater mode in the same room as the tv (router is downstairs). I'm able to connect the speakers to the tv using the menu > sound > speaker list option however, sound regularly either drops out and reverts to the built in tv speaker or stops working in stereo and reduces the volume of the right speaker slightly. Sometimes able to fix by turning the tv off then back in and reselecting the speakers but this doesn't always work. Any suggestions?