If you check the  [Debugger/Basic/Debugging font size follows main editor] box in the settings, then this change takes effect only if the settings window is closed by pressing the [Ok] button on the [Text Editor/Font and Colors] page. Moreover, after completing the debugging session, the new session works again with a font size that differs from the font size of the editor, and it can be changed only by opening the settings window on the [Text Editor/Font and Colors] page and clicking [Ok] (even if no changes are made in settings).