Cell behavior

Can editing a cell or even activating a cell ,ie, double clicking it, be prevented from slightly expanding the font temporarily. Once I leave the cell and go to another it returns to its original font but this behavior has come to my attention recently and proved to be problematic. Is this a new feature from an upgrade (currently 6.3) or some setting I turned on or just a limitation?

I didn’t clearly understand your issue. But listing it under “strange behaviour” I would lik to aks if you already tested wihout your probably cotrupted user profile (>Help>Restart in Safe Mode…).

Alleluia! Your suggestion to create a new user profile worked. Thanks!!!