“Authentication Required” prevents me from editing

I’m using V 2.8

Things used to work fine – no changes on my end.

I can successfully log-in to my control panel and edit the text of a “Post.”

The problem is I can no longer save the change.

I get defeated by a pop-up box “Authentication Required”,asking me for a user name and password. When I enter my own ID for the Control Panel, it rejects it.

It does seem to be providing some sort of PW hint or something. It offers a word in parentheses “magic”, which is a word I have never used as a hint. This is how it is phrased: “The site says, “magic.”

I’m hoping I haven’t been hacked. I have had a lot of rogue, comment spammers joining lately.

Thanks in advance for any help!