Hello,
Sorry to hear you are having issues. I tested on my Windows 11 V22h2 (OS Build 22621.900) with taskbar on top. And, I can still drag and drop from my desktop into the taskbar to pin it. Would like to suggest do this. Uninstall Start11, reboot immediately, download again latest version from your product account. Install that version, reboot again. Retest and report back.
Thanks
Basj,
Stardock Community Assistant.