Thank you for your comments and suggestions. I'm still looking at a replacement and have seen suggestions for the newish Cary 650 and the 432 EVO. I may abandon my search for hdmi if I can use a toslink cable successfully for two channel audio from the tv. I may return the Rose because of the hdmi issue and difficulties in figuring out certain operations, such as transferring music files to internal storage.
I notice I'm not the only one with audio issues (dropouts) using the Rose 150b connected to an LG OLED tv. So I decided to switch out the LG tv for a Samsung connected to the Hifi Rose and there were no audio issues. I used the same cables, inputs outputs, and settings, changing only the tv. It seems the problem may be with LG or Hifi Rose, or the communication between the two by hdmi.