conditionally visible drop down field values not loading

Issue: On a custom guided process page, field list-of-values (LOV) fields do not populate with values when the field was initially hidden and later was made visible conditional based on other field value..

Scope: Only observed on the guided process page. Not reproduced on the standard SR edit page.

Workaround: Selecting a different value in the parent field, then reselecting the intended value, causes the dependent LOVs to populate correctly.

Tested and confirmed broken: Conditionally hiding/showing the dependent fields based on the parent field's value, tested via two separate mechanisms. Layout rules and Business rules both had similar behaviour.