EDITED TO MAKE IT MORE CLEAR:
I have two browser games that are built using the same "engine". One uses the C2 runtime. The other uses the new C3 runtime. Both games run at 1920 x 1080, using scale inner for the display. (I use the browser object to change to full screen, this may negate the display setting.)
I have two laptops, both running 1920 x 1080 resolution. Chrome zoom is at 100% on both machines. Display "scaling" is at 125% on both machines.
Using the C2 runtime, the full game screen is visible on both games. Using the C3 runtime, one of the laptops looks fine, but the other is only showing about 80% of the screen. (I can see the full screen only by pressing CTRL- to zoom out to 80%.)
Any ideas why this is happening? I'm thinking there might be a setting problem with one of the machines, but I have no idea which one. (Note that I tried the display scaling already.)
UPDATE: I tried changing back to the C2 runtime but I was still having the same issues. (Last year's game worked fine, so I'm not sure what I changed.)
SOLVED: The issue seemed to be related to me going to full screen mode, so I checked the Browser object's settings and found that I was using "Centered" for the diplay. When I changed to "Scale Inner" it fixed my problem!