Switchin from Libreoffice calc windows to another window and return will cause
the current selected cell to be cleared on any keys press.

Reproducible: always

Step:
On Calc, type anything in a cell.
Switch to another window, alt+tab or with mouse press.
Switch again to Calc.
Press Alt, shift, tab, arrows, a key that should not perform a editing on the
cell.
With alt, Ctrl, Tab the cell will be cleared and will go in editing mode
With any navigation key, arrows, home, end, tab, the current cell will be
cleared and a new cell will be selected according to the key pressed.