Your previous post about that and VLC made me dig deeper in to why I never have had subs or CC in ChannelsDVR, but he did in Tivimate. I did change the user agent in Tivimate, and most channels do work. FWIW, I'm on an Nvidia Shield Pro, evidently he's on another device, judging by his added "ENGLISH" selection in the CC dialogue he posted a pic of.
Long story short, it makes me wonder if a feature request is in order, or even possible, for CHDVR? It seems to be as simple as making your user agent "VLC" to make CC and subs work for Pluto when using Tivimate.
Also, apologies for veering off-topic here, I just happened to recall past Pluto/CC/subtitle posts and also have an oddball limited use for Tivimate, so I decided to investigate.