Steps to reproduce:

1. Create a dependent item "item1" of numeric (unsigned) type, set Show value to "TruthValue", item gets values 0 or 1.
2. Create a calculated item "item2" of numeric (unsigned) type, set Formula to '1-last("test:item1")' and Show value to "TruthValue".
3. Display Latest data.

Result:
Last value of item1 is shown with mapping like "false (0)" or "true (1)", item2 is shown without mapping, just "0" or "1".
Expected:
Last value of item2 should be shown with mapping like item1.