iOS on-screen volume indicator stuck on screen

[clowNay]

• Device Name: iPhone 12 Pro
• Device Version: 14.4.2
• Browser Name: iOS Safari
• Browser Version: 14
• NoSleep.js Version: 12

Expected Behavior

Expected on-screen volume indicator to disappear.

Actual Behavior

on-screen volume indicator is stuck on screen for a very long time.

How Do We Reproduce?

Turning volume up and down when noSleep is enabled.

[vivipeder]

it's the same with me ...