It could be a UI problem. You can try the following approach to use buttons to edit the option value:
– remove power from OpenSprinkler, then power it back on, as soon as you see the OpenSprinkler logo, press and hold the third pushbutton (B3) and continue holding until it shows ‘Setup Options’.
– click B3 as many times as you need until it goes to the ‘Boost Time’ option. Then use B1 or B2 to change the value
– when you are done, please press and hold button B3 again until the controller reboots itself.
If this still doesn’t work, it’s likely a flash memory problem. You may have to do a factory reset. Before factory reset, please save a copy of your configurations so you can recover the settings later. Factory reset and import/export configurations are all explained in the user manual.