3.6.0 LCalc display formula instead of the actual result

LibreCalc 3.6 cell displays a formula instead of the actual result. Is it a change in behaviour or a bug?

Column F
4
5
6
=sum(F1:F3)

Platform Ubuntu Linux 10.04.

Verify in Menu/Tools/Options/Calc/View - Display - Formulas

Resolved. Thank you very much!