When you adjusts the volume slider in Control Center using the flick gesture, VoiceOver announces the previous volume level rather than the new level after the adjustment. Specifically, when a user focuses on the volume slider in Control Center with VoiceOver enabled, then performs a 1 finger flick up or down to change the volume, VoiceOver speaks the volume percentage. However, instead of announcing the new volume level, VoiceOver reads out the volume level prior to the flick gesture adjustment.
This results in an inaccurate experience for VoiceOver users, who expect VoiceOver to read the new volume level after adjusting the slider. The feedback does not match the actual adjusted volume.