I make use of the boost setting as I have a soil moisture meter ( from Ecowitt ) that alerts me when there is low moisture in the soil. I then use the Boost function to trigger an extra bit of watering for whichever zone needs it.
The boost function has stopped working, not sure when this happened, it might have been with the most recent code update.

All zones work fine on the schedule and when I go to the control unit and press the buttons, just not when I set a boost for a zone.