In the new update, the rear speaker connection of the samsung soundbar Q990b is not cut, checked in two days.. Now the surround mod and adaptive mod are more enjoyable, Thank God! :
Samsung Soundbar reset ARC not working fix - YouTube
HW-Q90R Samsung | Harman/Kardon 7.1.4ch Soundbar with Dolby Atmos Home Theater - HW-Q90R/ZA | Samsung US
Solved: 1010.5 Firmware Update for hw-Q70R/hw-Q80R/hw-Q90R Soundbars - Page 38 - Samsung Community