Good King Henry is not that great to eat and I am someone who loves their greens. It is very stringy and even my chickens refused to touch it
I can’t remember how it was to get going, but it still pops up on my plot now and then, so maybe you just got duff seeds.
I’ve grown Salsola (which I think is the same thing) as well. It was nice to eat but the seeds are difficult to get going. I think the advice on the pack I had was to soak them overnight, but even so I got very few plants for all the seeds I sowed. I decided it was not worth the effort of messing around.