I couldn’t find any documentation on this.

I’ve tried fixing this via disabling the Chrome flag “Omnibox refined focus state UI” someone mentioned in a 3 year old post but that flag doesn’t exist anymore.

Also, I’ve made sure the blue border isn’t the result of the Windows setting that applies accent colors to title bars and window borders. Additionally, I’ve tried enabling said settings to apply a less annoying color to that border, but that didn’t work.

Windows 10