Comment by SoftTalker

OWA (Outlook Web Access) shows me the antiquated "lite HTML" interface with Firefox on my OS. If I change the user agent to claim to be Chrome on Windows, it shows me the modern UI (which works fine, however it gets the time zone wrong).

Accessing Google Docs, Sheets, etc. works OK with Firefox, but if I claim to be Chrome some things don't work. So they are defintely serving up something different to Chrome vs Firefox browsers.