Custom Fields are no longer sorted

[Tom_Madison]

Up until recently, the custom fields were displaying in the correct sorted order.  Now, they are no longer sorted.  They appear to be displayed in a very random order.  I have tried editing them to sort them, but that does not work.  Somewhere I read that re-indexing could fix the problem.  I cannot find out where this re-indexing functionality is. I'm at a loss.

[Nic Brough -Adaptavist-]

Where is this happening?

[Tom_Madison]

In the drop-down menu selections.  The options are appearing in a random order, they used to be in the order that was specified, now they are not.

[Tom_Madison]

Here is a portion of our custom Developer field: 

See how the values are sorted (alphabetically).  Here is how they appear on the screens:

They're in no particular order.  They used to be.