Hello AgentVinh and Victor,
I had been trying to transition for ADFS over to Azure AD for SSO, I had created 3 instance in Azure AD Enterprise Apps and imported the Metadata in to three different SSO profiles in Hornbill Admin however this didn't work, i was getting and Cert trust error.
To fix this I just setup one SSO Profile in both Azure AD and Hornbill Admin and added all three Identifier (Entity ID) URLs to the SSO profile in Azure AD, once that was done all was working.
Now that I think about this it makes sense as when I had 3 profiles in both Hornbill would pass the auth to Azure AD which completed the auth and then send back a SSL Cert that hornbill received and as there was three profiles setup in Hornbill it didn't know which one to match it to.
I did try having just the one SSO Profile in Hornbill and three in Azure AD but that didn't work ether, again because each Azure Profile had its own Cert and Hornbill only trusted the one.
Hope that this helps someone else.
Cheers,
Graham