R7FSS3A77C3A01CFB GPIO pin 313 conflict with P306


I'm develop a custom board using S3A7 with part# R7FSS3A77C3A01CFB.

I configure pin P306 and pin P313 to be all output mode

Below is how I define the pin

#define PCNTR1_BASE                     (uint32_t)0x00010000

#define ADG1414_CS                        PCNTR1_BASE << 6

#define ADC_ADS1258_CS               PCNTR1_BASE << 13

if I toggle P313 low using register, 


then P306 will be pulled LOW and won't toggle HIGH regardless what method I'm using i.e.


or g_ioport.p_api->pinWrite(IOPORT_PORT_03_PIN_06, IOPORT_LEVEL_HIGH);


However, if I use the method below

g_ioport.p_api->pinWrite(IOPORT_PORT_03_PIN_13, IOPORT_LEVEL_LOW);

to toggle pin P313 low, then P306 won't be effected. What would be the reason? I have tried on few of our boards and they all act the same. I need to use register access so the pin can toggle faster.