I have the same problem reported widely across a number of Samsung soundbars where the connection between the TV and the soundbar keeps disconnecting and the TV resorts to outputting sound via its own internal speakers.
Has a solution been found? Has Samsung even acknowledged the fault that so many customers have reported actually exists?
I have a Samsung Q90T TV and a Samsung HW-S60T soundbar.
I had problems when I initially set them up - I remember learning that Samsung soundbars had this defect then - I can't remember the precise details of the workaround the community came up with (If I recall properly, Samsung just denied the problem existed) was to not use Arc - and accept degraded performance.
Anyway, cut to now, and the problem has appeared again.
I thought I might try updating the soundbar software, but that revealed more Samsung defects! I can add the soundbar to SmartThings (and it works fine for checking its status etc) but it won't connect to the TV via WiFi (and in the process, the software then disables the soundbar in SmartThings, stating the soundbar is "offline" - until you remove the soundbar from Smart Things.
This is one of those Samsung problems where you start off wanting do so something simple - just have the Samsung TV play sound through the Samsung soundbar - and then all the Samsung failings take you down a spiral - to get it working you need to update the software - that doesn't work.
To do that you need to connect the soundbar to the Wifi. That doesn't work.
To do that you need to connect the soundbar to the TV using Smart Things. That doesn't work. The software actually disables the functionality there was there before.
Crunchingly frustrating.
