SolidWorks 2015, SP 2.1

Background:  Making a bent Lexan guard for a machine.

Workflow:  Make Lexan panel as sheet metal (since it has a bend in it).  Unfold, make clearance cutouts for other equipment, Fold.  Here's what it should look like:

Bug:  Pushing Rebuild (Ctrl-Q) causes the Unfold to fail.  If I go edit the properties of the Fold (and the Unfold), it's lost the Bend:

I changed the K Factor at some point although I'm not sure if that has anything to with this.

Every time I push Ctrl-Q, this number increments by 1:

...So I assume the ID of the bend is being lost for whatever reason on a rebuild, which causes the Unfold and Fold to "forget" what the bend is.  Why would the bend increment like this?

You can simulate this for yourself by rolling back as I have done above and push Ctrl-Q.  You will see this number climb skyward.

(I prefer to model this way (Sheet Metal > Unfold > Make Cuts and Holes > Fold) because then the Hole Wizard correctly calls out the right number of holes in the flat pattern.  Also makes cuts that go across the bend line much simpler/more robust)