iOS it has rings and weird compression - quite noticeable
Chrome+Firefox Android has some mild patterning - less noticeable
Chrome, Firefox and Gnome Web on desktop are completely fine, so I'm thinking the issue on Android at least may just be due to #2. That effect is marginally worse on iOS so it's not impossible it's causing this issue as well.
Possible solutions: Fix #2, switch to a different background blurring algorithm (eg full Gaussian blur rather than quick, box blur, etc)
iOS it has rings and weird compression - quite noticeable
Chrome+Firefox Android has some mild patterning - less noticeable
Chrome, Firefox and Gnome Web on desktop are completely fine, so I'm thinking the issue on Android at least may just be due to #2. That effect is marginally worse on iOS so it's not impossible it's causing this issue as well.
Possible solutions: Fix #2, switch to a different background blurring algorithm (eg full Gaussian blur rather than quick, box blur, etc)