This is related to community post: "Couldn't verify your authorization to access this page" that have been closed.
The user in question (Maciej Reszotnik (RSZ) / rsz@kmd.dk) still cannot logon to sonarcloud.
When he was added as a member in SonarCloud he was getting this:
I have received your login issue and am currently investigating it. Once I have identified a solution, I will update you so that you can test the login access again.