Acrobat Pro DC - updated, but missing tabs preference option

This is a freshly downloaded and installed version of Acrobat Pro DC on a Mac running OS 10.12.5 that is also fully updated. I was surprised when opening several PDFs at once that they all opened in separate windows, so I opened Prefs > General. However, the line for tabs is missing - see below. I've checked to make sure it's the current version, and About... shows the version as 2015.006.30306 - the current version. If I go to Help > Check for Updates, a window pops up with a progress bar for a split second and is then replaced by an alert that says "Adobe Acrobat is already up to date." See below for screenshots.

I recently migrated to this computer using a Time Machine backup, so I was thinking there might be a permissions problem. I uninstalled Acrobat Pro DC and removed all files related to it in ~/Libary/Application Support/Adobe, ~/Library/Preferences, and ~/Library/Preferences/Acrobat. Reinstalling Acrobat Pro DC and checking for updates yields the same results - it's the most current version, but has no tabs preference.

I have a copy of Acrobat XI installed (my office uses this for a legacy copy-editing process), but as far as I can tell, they are not interacting with each other. I don't have any other Adobe products installed outside of what comes in the Acrobat Pro DC installer - Acrobat, Distiller, and Uninstaller - i.e. no Creative Cloud, etc. I enter my serial # when installing, so it should be updating if any updates are available. Any idea what is going on?