Stamps in Acrobat DC

I have a new work computer and have pdf's of custom stamp symbols that we use to mark up maps.  Since our upgrade from Acrobat 12 to Acrobat DC, I have not been able to see or use the stamps from these pdf's.

I do have the stamp files located in the C:\Users\User Name\AppData\Roaming\Adobe\Acrobat\DC\Stamps directory.  I searched the forums and confirmed that this is the correct directory.

It used to be that I would see the name of the particular pdf as a directory - say Fiber -- then when I would go to stamps -> Fiber I would see all of my stamp images.  Now I do not see them at all.  I tried to do the import, but that is 1 symbol at a time and will take forever.

Any help that you could provide would be greatly appreciated.  We have multiple users that are doing other work arounds until we can figure this out.

Thanks!