There was an Assistant update today (v4.1.3) which partially broke the Assistant in Edge and Firefox. Check for update in AdGuard (and make sure the AdGuard Assistant extension is updated to v4.1.4) and CLEAR your browser's cache. Doing this will make the Assistant function and look correct again.
Can you please tell me how to update the assistant? Adguard is saying it is up to date. But if I click on the Assistant it says I have version 4.0.16. I don't see any way to get an update for the Assistant.
Once I switched over to the Beta Channel I got my AdGuard Shield Overlay back. I am using Firefox on the Beta Channel (version 59.0 Beta 11). The only ting I am missing now is the Windows System Tray Icon. I read somewhere in GitHub that there was an issue with the SysTray I con breaking when utilizing Bitlocker Encryption. So they disabled it for the time being. To remedy the fact for now I just Pinned the program's icon to my taskbar.
Also, if you switch to the beta channel and or update or change browsers by uninstalling and then re-installing a different flavor or version of the same flavor browser make it a habit to re-initialize the AdGuard Certificate(s) under the "Network" setting of the AdGuard program. Sometimes the link between the browser(s) and AdGuard program will "break" or sever the SSL connection, FYI...