On 2 different Roku boxes I get no audio on 1 channel (only one channel, I think). The particular channel is WBOC which is channel 806/1016 on my system which in this case serves Lewes DE.
Right now Comcast is totally overloaded, probably due to everyone at home due to Coronavirus. My Internet has been going in and out, although there is no reason to believe that this problem is related to that, since other channels audio is fine. Weirdly, I do get audio on Comcast DVR/STB and also on PC that is connected by Xfinity web page streaming.