Hello,
Sorry to hear you are having issues. But, on my system, I tested on "Snipping Tool" and it does show Pin to taskbar on my system.

Perhaps something not get install properly, please try, uninstall Start11, reboot immediately (important), download latest version available in your account product download page: https://store.stardock.com/myaccount/products. Install it, reboot immediately again. Retest it and report back.
Thank you,
Basj,
Stardock Community Assistant.