This doesn’t track at all if you are talking about the same device! If volume was fine in 2017 and its low in 2019 it isn’t as though they reached out and changed the chip in your device.
The volume of recording on my Tablo 4 tuner are very low compared to everything else. On my Roku TV, on my, PC, and on my Android devices. Even if there is a chip in the Tablo that causes low volume it can be boosted in software on the device playing the media. They could add some kind of option to boost volume so it matches everything else.
Last I looked my Roku TV still didn’t have that option. I should check it again. That of course won’t help on my other devices.
The low volume issue is extremely annoying. I often have the volume turned all the way up to get decent volume and then we switch apps or input and get blown out of the house.