SYSTEMConfigPerformance not executing in PIC32
SYSTEMConfigPerformance() also sets the FPB (peripheral bus frequency) divider to the highest performance value, in this case the same as your system clock, so it is running at 72 MHz instead of your expected 36 MHz, thus your baud rate assumptions are incorrect.

You can instead call the following function, and leave out the PB bus configuration flag:

SYSTEMConfig(FCY, SYS_CFG_WAIT_STATES | SYS_CFG_PCACHE);


The other option is to just run the peripheral bus at the 72 MHz instead, and just change your #define value:

#define FPB (FCY)