Comment 9 for bug 1652822

... Ah I see, it does look like possibly the debian upstream might have fixed it, and merely the ubuntu package has not yet got it. Which is what this bug declares at the top, so no discrepency there after all.

They mention signed images, where in my own case I have uefi boot security disabled and can boot unsigned things, so I don't know if that fix will still fix me or not, but seems likely.