The problem is that the LcdFont.LCD only contains numbers which is not appropriate for the Textmode. Therefor you have to set the valueFont to something different e.g. LcdFont.DIGITAL or LcdFont.Elektra etc.
I modified the code in LcdSkin so that if textMode == true -> setValueFont(LcdFont.Digital). But you can also override this by either using the LcdBuilder.valueFont(LcdFont.Elektra).