Private listening volume too quiet

I like the private listening feature, but the volume level and quality is variable between apps. For example, when using private listening with YouTube, the volume level is quite low even at maximum volume. When using private listening with Amazon Prime Video, the volume gets much louder and sounds much better. The volume is also low for HBO Max. I just got AirPod Max headphones and the volume can get very loud when I listen to music on Spotify or YouTube or other apps on my iPhone, so I know the headphones can get louder than they are when using Roku private listening. I connected my Bluetooth headphones to an Apple TV at my parents house and the sound quality was amazing, so I think it’s either a problem with Roku private listening overall or the way that each app (YouTube, Amazon Prime Video, HBO Max, etc) deals with the audio for private listening.