An example of what will cause it:

#define DISPLAY_COMMS_RESET_RX()	DisplayCommsRxResponsesReceived = 0; DisplayCommsRxResponseByte = 0; DisplayCommsResponsesChecked = 0

Ideally you’d call a function instead, but there is a recommended workaround:

#define DISPLAY_COMMS_RESET_RX()	do {DisplayCommsRxResponsesReceived = 0; DisplayCommsRxResponseByte = 0; DisplayCommsResponsesChecked = 0;} while (0)