I have a constraint enabled on a field.  This is working as intended in that it allows two numbers, a dash, two numbers, and a possible letter.

Here it is working in the template:

I am reprocessing a bunch of old documents that also have another minutes number field with no constraint.  For example:

I have a workflow that simply pattern matches off the first two digits and the second two digits and uses an assign field values to flip the template and put the minute number in the new field.

No matter what I seem to try, the workflow fails with:

It is failing on setting the number into the new constraint field.  Everything looks fine and I have tried a variety of ways.

Here is the assign field values item:

Here are the tokens:

I have tried putting both in a token and then using the token to assign to the field but also get an error.  

I have tried formatting the token as a number and get an error.

I have tried both with and without the dash and get an error.

I have tried removing the constraint from the field and it assigns correctly.  Then I have tried to re-enable the constraint and get an error saying that the current field data does not follow it.  Clearly it does follow it from the screenshot above.  Note I am only testing with one document so I know there is nothing else in here.

I am out of ideas for something that seems to be pretty straight forward.  Is there anything I am missing here?  

Thanks

Chris