Broken Tib/Fib with cramping

I recently severly broke my tib and fib.
The fracture/break is stable and my doctor has me in an air cast with no weight bearing.
The bones don’t ache or hurt like they did when I had a trimalleolar fracture 4 months ago.
However, I am experiencing painful cramping in my calves and ankles.
Is this normal?
It is extremely annoying and disrupts normal activity, even my sleep.