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We cannot fix this!
This is a bug in their products, and has to do with the way user licenses are handled. (Yes, they claim to have fixed it, but they have not.) We have accomodated this as best we can by allowing non-public email addresses to immediately add themselves into our site, buf if you rely on a public email provider, that simply doesn't work and you will generally need to logout of Atlassian, or use a private browsing window, to access the site.
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