Similar display in my Chromebook. An old Chromebook but (of course) always updated and I believe the browser (Chrome) is still following the latest standards although probably different than the ones on Windows etc.
Yes it's only on Upwork website from as far as I can see.
It's probably Upwork, who use some non-standard or experimental CSS.
And no the "solution to all problems" (cookie clearing etc) doesn't work for me.