drv_sst26.c has an issue with PIC32MZ (probably others MCU). The line SQI_BDCTRL_SQICS_CS1 is used by default and it seems there are no options in Harmony 3 Configurator to use SQICS0 instead of SQICS1.
When every occurrence of SQI_BDCTRL_SQICS_CS1 is substitute with SQI_BDCTRL_SQICS_CS0 the CS0 line work properly.
drv_sst26.c has an issue with PIC32MZ (probably others MCU). The line SQI_BDCTRL_SQICS_CS1 is used by default and it seems there are no options in Harmony 3 Configurator to use SQICS0 instead of SQICS1. When every occurrence of SQI_BDCTRL_SQICS_CS1 is substitute with SQI_BDCTRL_SQICS_CS0 the CS0 line work properly.
Luca