Apple watch Green Notification screen

I ordered a new Apple watch series 8 midnight color 45mm. I faced issues with the sceen from day 1. on the notification screen and the screen you drag from bottom, on left side the 1/3rd of whole screen gets GREEN. Sometimes its there in day light but mostly in complete dark this issue is there.

I returned the watch to apple Genius bar they returned it back saying NO issues found, but I can see that same thing next day. so i returned the watch to Target.

Today I got my new watch from Target and exactly the same issue is there, 1/3rd of Notification screen is turning GREEN in dark.

Any suggestions what might be the issue? is it with every watch is just with me?