Sorry, I didn't see the link. It doesn't look like what I was thinking it might be, and there doesn't look like anything totally obvious going on. The leaf cupping in the second picture could possibly be a sign of too much water. On first year rhizomes, once they're up and running, I normally wait a week or so and if we get no rain - water very slowly for a long duration to make sure the soil is moistened real deep. Use a soaker or just crack the end of the nozzle so there's a very fine mist and let it go for a half hour or so. I generally try to let them go with no water until the leaves just barely start showing the slightest bit of wilt - that's just me though. Your soil makeup will affect your watering patterns. Deep watering as opposed to shallow frequent watering will help develop deeper stronger roots during establishment. If it's not a water problem it could have something to do with the soil which I like to amend to at least a foot or more with lots of organic matter for starting rhizomes. Diagnosing plant problems can be very difficult due to lots and lots of variables. Sorry we couldn't nail something down.