I do not know what it is with me and my garden and Stiletto. I have killed it twice. I ordered it again from Hallson 2 yrs ago and last year I dug what little was there and put it in a pot and it is struggling to survive. I have had the same problem with Kabitan. Cannot keep those two alive.
I found that if a hosta is struggling I put it in my home made compost put it in full sun and keep it moist. That seems to be the only think that is helping Stiletto to do a little better.
I really like 'Roller Coaster Ride'