Did anything happen before you began having issues logging in? Like new plugin activated, or updated plugins, WP core, etc. Or did it just start happening out of nowhere?

Try to login to your site using Chrome Incognito mode, or Firefox Private browsing mode. Just to make sure it’s not a browser setting issue or some rogue cookies/cache that wasn’t cleared/deleted.

Thanks.

Unfotrunately, i managed to use the admin on a mobile device and thought that I’ll use my backup to restore the settings When everything Was ok.

And then The updraft plus plug-in destroyed my database. From what i reda on their forum, it is a common issue. The plugin is clearly not up to date with new msql versions and the utf8mb4 character set

https://victorfont.com/updraftplus-failure-to-restore/

Is There any way you can help me?