Some Google Pixel phones are facing an annoying display bug
The recent Feature Drop could be to blame

Google rolled out the March Pixel Feature Drop earlier this week, bringing some minor but crucial improvements, while also patching a few bugs in the process. But as with most new releases, some bugs can pass through the filters and appear in the final release. We've already reported on a haptics-related change that came bundled with the update, though it's still unclear if this was a deliberate inclusion or a bug that slipped through the cracks. Multiple user reports on Reddit now suggest that Google may have an actual bug to deal with, one that primarily affects video viewing.