This is pretty common and you're definitely not alone. Steep grades require more strength. Your cadence will naturally decrease on the steep stuff and it takes more muscle to keep the pedals turning. It's pretty much the same reason Philippe Gilbert can drop the Schlecks on the steep finish at Liege Baston Liege but the Schlecks drop him in the Alps. Different horses for different courses.


If you want to get better at steep grades, ride more of them more frequently.