Having the same problem on 6.7.4.5741. Set my default font to Calibri, size 11, about 10 days ago. For the first week the font window insisted on showing Segoe Size 10. I finally managed to trick it into show the correct information in the menu bar. When I'm typing, the system will randomly revert to size 10 in the middle of a line or sentence. It's obvious the font size has changed, but the system still shows size 11 in the menu bar. I have to select all text and manually select 11 and the text in the wrong size will switch back. A few minutes later I have to repeat the process.