Mellon logout endpoint - ProviderID not found

[everderio]

I have succesfully configured mellon for IDP and SP
I can succesfully do the manual login /mellon/login?ReturnTo=/mysite
but when I call the logout function with /mellon/logoiut?ReturnTo=/logout.html I get the following error logged by apache:

[auth_mellon:debug] [pid 13264] auth_mellon_handler.c(278): [client 10.40.176.21:17383] loaded IdP "https://b2cpoc.onmicrosoft.com/" from "/etc/apache2/mellon/metadata.xml".
[auth_mellon:error] [pid 13264] [client 10.40.176.21:17383] Unable to create logout request. Lasso error: [-408] ProviderID not found

Thank you and kind regards

[ThemGit]

try using the whole ReturnTo URL

https://mysite.com/mellon/endpoint/logout?ReturnTo=https://mysite.com/logout

Not sure if it's gonna help anyone so much later, but I had issues on this until I had the correct URL