Right-click in Windows 10 taskbar not working for 1 program (Acrobat)

Using Windows 10, right-clicking on the Adobe Acrobat X Pro icon in the taskbar stopped working. Right-clicking other program icons continues to work fine, including other Adobe programs. Right clicking on Acrobat X worked fine before yesterday. I used the "Repair Acrobat Installation" button in Acrobat, nothing changed. I updated Windows 10, nothing changed. I restarted the computer several times, nothing changed. It appears something is happening when I right click because for the tiniest split second my screen displays the churning blue wheel as if it were trying to access some file, but then nothing happens. Other than this right click issue, Adobe seems to be working fine. In fact, I don't think it's an Adobe problem at all, but instead Windows trying to access some file that's missing.

Anyone know what might be causing this? Is it an Adobe problem or a Windows problem? What action does right-clicking trigger? Is Windows looking for some missing file?

After trying about 20 more things that didn't work, I finally solved it by doing this:
1. I unpinned Acrobat from the taskbar.
2. Then, I placed a PDF file on my desktop (a filetype that automatically opens with Acrobat).
3. Then, while Acrobat was NOT open, and not pinned to taskbar, I dragged the PDF file from the desktop to the taskbar. Doing this caused Windows to recognize Acrobat as a new program to pin to the taskbar and with that, the right-click function was also restored.