I have plants from a couple of sources in the UK, and they seem to me to be infected with a virus. The leaves and shoots have yellow stripes that seem like fairly typical virus symptoms. I am a little sensitive to viral problems, many of my Cannas had a final trip to the bonfire last year because of viral problems.
If it is a virus, it doesn't seem to reduce its vigour at all, but I still keep this one in a cold greenhouse on its own, where it is less likely to infect anything else. I would be interested in hearing from other growers, to see if it is a local or global problem.
This is such a pretty old hybrid, that it would be nice to think that there is still clean stock somewhere.
I have recently been sent a plant from Puerto Rico that show the telltale streaks in the leaves so it may be worldwide.