Banding problem

Hi,

We’v got some serious issue when we used gradient or blur, banding appear on display and on output.
The only way we found is to used Dither node…Is a patch, not solution !

I 've not find any properties on project settings to change bit depth, same with general préférences.
have you got any idea ?

regards,

Harmony 17 premium
windows 10 pro x64
no tweaks, harmony 17 factory setup