I am experiencing the same. Security challenge is working on iOS app, not on Chrome desktop. All my passwords are suddenly 'weak', although they were fine a few days ago. I checked and the passwords are still what they were before. I renewed one of the passwords to test whether it improves anything. Extended the length of it just to be sure, but still have same amount of 'weak' passwords. Hoping this will be fixed by developers soon.
I was having this problem for 2-3 days, so I sent them a request... 3hrs later they sent a messages to me saying 'clear browser cache and remove cookies'... BEFORE I did that I tried it again and it suddenly worked fine... so I'm guessing they 'fixed' something and then just sent that out to me 😞
Yep, the missing username problem is suddenly fixed for me as well! I tried it again this morning and it just works now (Chrome browser on a Mac). Does that indicate the plugin was silently updated, or was this a break/fix on the LastPass server side? Do company support reps ever chime in on these forums?