My jackmanii dies back to the ground. When you cut the stems, were they green on the inside?

If I remember correctly, jackmanii is a little late to get going. If the temperatures are still around or below freezing at night, I might take a while before you see shoots coming up from the soil.

Is the plant located in a sunny exposure or is it in a sunny one? If in a shady exposure right now, that could lengthen the time when it sprouts. Your air temps may have warmed up but the soil might not have. Patience grasshopper.

Jackmanii is not an early clem for me and blooms midsummer- those will get growth going in a few weeks.