Olivia hi,
just a quick note. After uninstalling Acrobat Reader and running Adobe's cleaning app (AdobeAcroCleaner_DC2021), I ran a registry check with CCleaner, restarted the computer and reinstalled Acrobat Reader from an offline installer. It now works properly.
Since I did the uninstall/reinstall process before (without the extended cleaning), my best guess is that something went wrong during an Adobe update (most likely the conversion from 32 to 64 bit).
Thanks regardless