Ssd1331.h library font size problem

I’m using the Adafruit_SSD1331.h library on a cheap colour 96x64 display and it works ok but only with display.setTextSize(2); and any other size such as 1 or 3 displays nothing.
I’ve seen mfGFX library but I don’t quite understand how to use it with this display, do I still require the SSD1331.h library to drive the screen?