On an older machine, I had PMM running and in the MySQL overview, I was able to select All hosts that displayed all of my hosts on a single graph. It was very nice to monitor. Since I installed PMM server on a new server, the 1st host is automatically selected in the hosts list, I can select others, but the All option is not there any linger.
Found the reason, seems this is now moved to the “Cross Servers Graph” dashboard, so all is ok.
Thanks Milos for letting us know - it may well help others in the future too!