Hi Yuriy,
About what Column Font are you talking about?
The grid font you change in the Edit>Preferences-Appearance tab sheet? If yes, make sure you have the Edit>Preferences-General SaveProgramStateWhenExit option checked, or PDFE will discard all preferences changes, and will run with default, or previous saved ones, on next session.
If is not this Font option, or the feature is not working for you, please give me more details.