I didn't contact support, but I have been able to cut SU's cardstock for two days!! Settings that worked for me both on a sunny day and a very damp rainy day: Dark colors: Blade @ 3.5; Pressure @ 23; Speed @ 3. Light colors: Blade @ 3; Pressure @ 21; Speed @ 3.
Hopefully, this information will give someone else a starting point.
Thanks for your suggestions. I really appreciated you taking the time to respond.