|I'm confused...your subject line asks why Calc is changing to smaller fonts yet your body text says the font stays at 14. Which is it?|
Do you mean that the Zoom level is changing, i.e. the size of the image that appears on the screen?
I don't use Calc, but a quick Google search doesn't seem to indicate that Backspace can be used as a Zoom shortcut key.
Try the normal stuff: close Calc, reboot, restart Calc, try a different Calc document , etc.
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