Ok, I found an answer to this one on my own. For anyone who might have the same problem, the fix is to edit the registry key for the layer manager window.
This is the registry location:
HKEY_CURRENT_USER\Software\<your windows profile name>\AutoCAD\R16.2\ACAD-4001:409\Profiles\<<Unnamed Profile>>\Dialogs\LayerManager
Change the "bounds" key value to something like:
100, 200, 700, 400
This worked for me.