Links to tabs in workbook not visible

A moth or so ago I put together a workbook for all of our locations to distribute out for associates to populate some basic information.  The first tab is the Master Tab and I had a list of all of the facility names and had them linked to their respective tab so users could just click the link to get to their page.

The workbook has been untouched since creation until today when I went to check it prior to distributing it.  When I opened it up the column with the linked names was blank!! When I clicked into a cell I could see the formula was still present in the formula bar, but nothing visible in the cell.

I went back a few versions and found one that had the links showing, but as soon as I unprotected the sheet they disappeared again.

Has anyone experienced this before? How do I save my work? 

This is the tutorial I followed: https://www.youtube.com/watch?v=ZZ9j8m1lT6w&t=18s😞

When I open an earlier version they are there:

But as soon as I unprotect the sheet they disappear again!  What gives?