Webpages won't display with correct aspect ratio

SETUP

I'm currently using an M1 Mac mini with Presenter 2026.1.0-beta.11. My main monitor resolution is 1920x1080p. I am outputting to a projector using a 4:3 aspect ratio (800 x 600). I know 4:3 is basically obsolete but that's what I have to work with.


PROBLEM

For scriptures, I set the template to 4:3 and that projects just fine, but when I use the "webpage" functionality it projects with black bars on the top and bottom, in 16:9 aspect ratio.


TROUBLESHOOTING

I assume presenter's outputting at the right resolution/aspect ratio because in "screen settings" the display reads "display 800x 600" (although there's no resolution setting to verify). Also, the scripture template displays 4:3 just fine.


QUESTION

How can I get my webpage to fill the 4:3 aspect ratio on my projector?

Thanks for any help!