People tags missing after editing.

I have extensive collection of photos in Organizer (+50,000).   Many from been there since I started with Elements 3 and have been brought forward through many upgrades.  Many of the old ones are still in PSE format.   I started a project in Elements 12 of editing them and saving in TIF format.   Now in Elements 18 when I save the edited photo the people tags are dropped.   Other tags carry forward put not the People tags.   It seems the file format is not the issue because if I save as JPG or any other format they are still lost.   If I edit a TIF file and then save in version set the tags are still lost.

What can I do to get this fixed?   Am I missing something?   Is this a bug in Elements?   Are others having this issue?

Herb Smith