A well used calc spread sheet returns as display in cell the text of the formula whenever the formula has been edited, and not the value of the formula calculation. Unedited formulas still return values (until edited).
Menu:Tools→Options⇒Options(Popup)⇝LibreOff Calc⇝View:Display:Formula Box is unchecked. Toggling this has no effect, except that text of formulas are displayed for all formulas when the box is checked.
Re-entering formula even using formula wizard has no effect.
The calc sheet has multiple sheets and cross sheet references.
Update: bug filed: https://bugs.freedesktop.org/show_bug.cgi?id=60755
I suspect this is a bug but bugzilla is down. Show stopper for this calc sheet.