Which browser loads the correct mobile display?

[Lilly]

yea the ?mobile_view=1 is legacy and considered deprecated - the newer mobile styling was enabled last year:

@system

Legacy Mobile / Desktop Modes

Historically, Discourse shipped two completely different layouts and stylesheets for “mobile” and “desktop” views, based on the browser’s user-agent. Developers would target these modes by putting CSS in specific mobile/desktop directories, by using the .mobile-view/.desktop-view HTML classes, and the site.mobileView boolean in JavaScript.

These techniques are now considered deprecated and should be replaced with the viewport and capability-based strategies discussed above. We will be removing the dedicated modes in the near future, making “mobile mode” an alias for “viewport width less than sm” for backwards compatibility.

not sure what you’ve done on your own forum for customizations, but i cannot repro this problem on any instance or device. does it do it in safe mode?