nRF52832 P0.10 GPIO Voltage drop

Question

Hi all, 
 I try to control IC by nRF52832. 
 [My Application] 
・Supply 2.5V to nRF52832 and IC. 
・Connect P0.10 to IRQ(IC) 
 [I did these setting] 
・Define "CONFIG_NFCT_PINS_AS_GPIOS" 
・P0.10 : INPUT, PULL DOWN 
 But, the IC's IRQ signal voltage drop.
If it is normal, it should be 2.5V. But it will be 1.8V.
(I confirmed that the P0.09 is operating as GPIO) 
 Please tell me if it need other settings. 
 [schematic] 
 
 [ADC_RDY signal (enable pull-down)] 
 
 [ADC_RDY signal (disable pull-down)]
 
 [ADC_RDY signal (enable pull-up)]
 
 [Setting of UICR] 
Code use library is "nRF5_SDK_13.1.0_7ca7556". 
 # C flags common to all targets
CFLAGS += -DBLE_STACK_SUPPORT_REQD
CFLAGS += -DBOARD_CUSTOM
CFLAGS += -DCONFIG_GPIO_AS_PINRESET
CFLAGS += -DCONFIG_NFCT_PINS_AS_GPIOS 
CFLAGS += -DNRF52
CFLAGS += -DNRF52832_XXAA
CFLAGS += -DNRF52_PAN_12
CFLAGS += -DNRF52_PAN_15
CFLAGS += -DNRF52_PAN_20
CFLAGS += -DNRF52_PAN_31
CFLAGS += -DNRF52_PAN_36
CFLAGS += -DNRF52_PAN_51
CFLAGS += -DNRF52_PAN_54
CFLAGS += -DNRF52_PAN_55
CFLAGS += -DNRF52_PAN_58
CFLAGS += -DNRF52_PAN_64
CFLAGS += -DNRF52_PAN_74
CFLAGS += -DNRF_SD_BLE_API_VERSION=4
CFLAGS += -DS132
CFLAGS += -DSOFTDEVICE_PRESENT
CFLAGS += -DSWI_DISABLE0
CFLAGS += -D__HEAP_SIZE=0
CFLAGS += -mcpu=cortex-m4
CFLAGS += -mthumb -mabi=aapcs
#CFLAGS += -Wall -Werror -O3 -g3
CFLAGS += -Wall -Werror -O0 -g3
#CFLAGS += -Werror -O0 -g3	#使ってない関数があるとエラーになるのが邪魔なら-Wallを消す
CFLAGS += -mfloat-abi=hard -mfpu=fpv4-sp-d16
CFLAGS += -fstack-usage	#stack size 確認
# keep every function in separate section, this allows linker to discard unused ones
CFLAGS += -ffunction-sections -fdata-sections -fno-strict-aliasing
CFLAGS += -fno-builtin --short-enums 

# C++ flags common to all targets
CXXFLAGS += \

# Assembler flags common to all targets
ASMFLAGS += -x assembler-with-cpp
ASMFLAGS += -DBLE_STACK_SUPPORT_REQD
ASMFLAGS += -DBOARD_CUSTOM
ASMFLAGS += -DCONFIG_GPIO_AS_PINRESET
ASMFLAGS += -DCONFIG_NFCT_PINS_AS_GPIOS 
ASMFLAGS += -DNRF52
ASMFLAGS += -DNRF52832_XXAA
ASMFLAGS += -DNRF52_PAN_12
ASMFLAGS += -DNRF52_PAN_15
ASMFLAGS += -DNRF52_PAN_20
ASMFLAGS += -DNRF52_PAN_31
ASMFLAGS += -DNRF52_PAN_36
ASMFLAGS += -DNRF52_PAN_51
ASMFLAGS += -DNRF52_PAN_54
ASMFLAGS += -DNRF52_PAN_55
ASMFLAGS += -DNRF52_PAN_58
ASMFLAGS += -DNRF52_PAN_64
ASMFLAGS += -DNRF52_PAN_74
ASMFLAGS += -DNRF_SD_BLE_API_VERSION=4
ASMFLAGS += -DS132
ASMFLAGS += -DSOFTDEVICE_PRESENT
ASMFLAGS += -DSWI_DISABLE0
ASMFLAGS += -D__HEAP_SIZE=0

# Linker flags
LDFLAGS += -mthumb -mabi=aapcs -L $(TEMPLATE_PATH) -T$(LINKER_SCRIPT)
LDFLAGS += -mcpu=cortex-m4
LDFLAGS += -mfloat-abi=hard -mfpu=fpv4-sp-d16
# let linker to dump unused sections
LDFLAGS += -Wl,--gc-sections
# use newlib in nano version
LDFLAGS += --specs=nano.specs -lc -lnosys
 
 [Setting of P0.10] 
Code use library is "nRF5_SDK_13.1.0_7ca7556". 
 nrf_drv_gpiote_in_config_t adc_rdy_config = GPIOTE_CONFIG_IN_SENSE_LOTOHI(true);
adc_rdy_config.pull = NRF_GPIO_PIN_PULLDOWN;
err_code = nrf_drv_gpiote_in_init(D_PIN_POS_ADC_RDY, &adc_rdy_config,f_afe_irq_event_handler);
APP_ERROR_CHECK(err_code);
 
 Thanks, 
Koh