The volume between 20%-100% regarding "Settings" > "Music & Sounds" > "Jukebox/Note Blocks", doesn't change the actual volume level. The volume is only noticeable between 0%-10%.
MC-189310
The volume between 20%-100% regarding "Juke Box / Note Blocks" doesn't change the actual volume level
Open
3
(Unassigned)
Confirmed
Sound
audio, settings
1.16 Pre-release 5, 1.21.1, 24w40a, 1.21.5
Retrieved
Of note: the full volume range does work, but currently-playing music discs are unaffected if the volume stays above 20%.
Also can confirm this still happens in 26.2