Black flickering

i am trying this sandbox Diamond refraction (forked) - CodeSandbox

i am having only one issue when the diamond is rotating there’s like a black flickering boxes that is visible anyone can help me to know why its happening

You should add which device + browser + platform you use. What you describe can often happen on mobile especially, driver or compatibility issues as well as bugs which can also happen with new released devices or browser updates.

i tried it on all devices keep giving me the same bug
did you try it ?
i am on chrome
windows 11

No issue on Chrome Windows 10, there is quite more though that can be the cause, the GPU, the actual device (Notebook, Desktop, Tablet etc) and again driver, Chrome version etc

if i turn off this

EffectComposer bloom
it wont happen anymore
but i need it