I don't know what the "east side of the house" means for sun exposure, but if it isn't getting 4-6 hours of good direct sun a day, it'll underperform. Mulching it, after cutting it down in the fall, could have subjected it to rotting over the winter.

I'm in the same zone, and my Miscanthus clumps have been sprouting for over a month. I cut them back just as they started sprouting, after leaving their fall foliage up all winter.

If you have a single blade, the clump is obviously still partially alive. You could just watch it, or you could dig it up, and divide out the section the single blade is growing from. Put it in a sunny spot, and wait.