I tried with the browser, but it didn't work. I can't "prevent portrait" via browser.
After several days of research and testing, I couldn't find anything conclusive either. Did you find a solution on your side?
no i did not search for it, since i don't think is a problem that users will face, and if they do they go back to where the game works ... which is normal landscape.
however i found this i guess u could high jack it for browser, but should work from C3 settings as well since does the same thing.
tip pulled from developers.mozilla
in browser u could add a condition ruling, saying: