How do I use internal 2V5 with attiny1606?

[JasXSL]

I keep getting way too low results when I use 2V5. Measuring the voltage on PIN_PA7 gives a stable 2.55V, yet analogRead won't go over 622. I'm sure it's something trivial I've overlooked, maybe someone could take a look?

Code:

const uint8_t PIN_BAT_EN = PIN_PC1;			// Active HIGH
const uint8_t PIN_BAT_IN = PIN_PA7;
void setup(){

	Serial.begin(9600);
	analogReference(INTERNAL2V5);
	analogReadResolution(10);
	pinMode(PIN_BAT_EN, OUTPUT);
	digitalWrite(PIN_BAT_EN, HIGH);
}

void loop(){

	analogRead(PIN_BAT_IN);

	uint16_t bat = 0;
	for( uint8_t i = 0; i < 10; ++i ){
		delay(2);
		const uint16_t reading = analogRead(PIN_BAT_IN);
		bat += reading;
		Serial.print(reading);
		Serial.print(", ");

	}
	bat = bat/10;

	Serial.print("Bat raw: ");
	Serial.println(bat);
	delay(2e3);

}

Circuit:

megaTinyCore 2.6.12

[JasXSL]

Turns out the MCU was bad. It worked fine after replacing it. The above example should be fully functioning.