Interesting. I checked it and it seems that the SSL/TLS options are still available for your sub-subdomains. That’s a bug in the control panel, because no matter what you upload there, the servers themselves won’t actually use it.
The intended behavior is that you get the same error message you see when you try to configure SSL for firaz-server-nexus.wuaze.com.
I’m sorry for the confusion caused by this bug. But the fact remains that sub-subdomains no longer support SSL, and there is no way around that.