I ran into some errors while renaming glyphs. For example I wanted to rename ff into f_f for the liga feature. After reselecting the particular glyph, its name has then automatically changed to ff.ss01.001. Selecting this name again and changing it back to f_f it then changes to ff.ss01.002.
This is only one example. I’ve also had this happen with currency signs, etc.
GL V. 2.4 (939)