does it also happen for you with a different browser?
It's a plain Chrome install with Darkreader and AdGuard installed.
I didn't bother trying another browser as the link that was emailed to me worked just fine.
when you reloaded you missed a setting ?
Nope. I've been stripping, rebuilding and re-installing Operating Systems on PC's since the late 80's, and so I know what I'm doing.
Bizarrely, I don't get the error anymore, and nothing has changed in the browser since I got that error.
imho, your browser simulates being a mobile version.
No, it's basically just a plain install of Chrome that produced that error. As mentioned above, I cannot reproduce the error now.