IDN SSL - SSL Domain saved wrong
If you have a IDN Domain (e.g. exämple.tld // xn--exmple-cua.tld) ISPConfig has a problem with saving the SSL Domain on SSL Tab. You can choose www.exämple.tld as SSL Domain and save it, but if you open the tab the next time, it will show exämple.tld as selected.
I've checked the DB entrie. If you select www.exämple.tld and save it, it gets stored with www.exämple.tld in the database and i think the drop down checks for www.xn--exmple-cua.tld and thats why there's no selected state on this select box.