Regression from 216593. That rev hard codes the User-Agent header to report MacOS X 10_15_6 on macOS 11.0+ which breaks Duo Security UA sniffing OS version check. Duo security check fails because latest version of macOS Catalina is 10.15.7 but 10.15.6 is being reported.
Created attachment 415012 [details] end user screenshot
*** This bug has been marked as a duplicate of bug 217364 ***