Different resolutions might reveal a slight pixel error, which becomes really apparent when relying on images being pixel-perfect.

To reproduce:
1. Open attached project
2. Open scene CharacterCustomization. It contains an example menu box that relies on images being pixel-perfect
3. Scale the gameview window to change the resolution. Notice that the top right corner of the menu has a bright blue line that's popping in and out of existence as the game view is being scaled

The situation can be improved by setting the canvas reference resolution to the game view resolution, but it might not help if a few resolutions are planned to be used