So after much effort trying to figure out why I can't seem to get much volume from my 2020 New Roku ultra private listening mode. It seems like it is working as designed.
On my bedroom TV with the 2019 Older Roku ultra that has the remote with private listening, the volume is great on the ear buds. I am "older" and require a louder setting on my earbuds than you younger folks. Not a lot but I need about a "70" volume setting as I like to be able to hear all the dialog and the background sound effects of what I am watching. it is extraordinarily loud at 100.
On my new roku that I just bought ( 2020 Model ) that I installed in my living room, when I run private listening mode with it's earbuds, volume does increase up to about "50" but then when I increase the volume on up past 50 to 100, the earbuds do not increase in volume. 100 is the same as 50.
So reboot, do a factory reset, what is your model, swap remotes between the 2, what is your older ultra model, swap earbuds, what App are you using, return the new box to best buy for a swap out.. all questions that I worked with support on and got nowhere with. All points to the Roku box.
So conclusion.. They wound down the sound driver on the new roku private listening mode..I can barely hear the sound thru my earbuds. I guess its so they don't get sued for for destroying someone's ears.