Hi Dan!
Reset the Adobe Reader's preferences once and reboot the machine, to reset the preferences, refer to the help article How to reset Acrobat Preference settings to default. See, if this brings any difference.
If the issue persists, navigate to Adobe Reader's Preference from Edit menu>Preferences>Security(Enhanced)>and uncheck these two options 'Enable Protected Mode at Startup' and 'Enable Enhanced Security'>Click OK. Close Adobe Reader and launch it back and check.
If you still experience any issue, use Acrobat cleaner tool to remove Adobe Reader Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs
Reboot the machine and install Adobe Reader from Adobe - Adobe Acrobat Reader DC Distribution
Once Adobe Reader is installed, download the latest patch of Adobe Reader 19.008.20080 from help>check for updates.
Let us know how it goes and share your observation.
Thanks,
Anand Sri.