Problem with Port 36,37,38,39 (WiFi LoRa 32 V1)

Hi there

I use this ADC-Ports as digital Inputs (36,37,38,39).

Here my Code:

/* Heltec LoRa V1
*/

#include “Arduino.h”
#include “heltec.h”
#include “images_Logo_Heltec.h” // Heltec Logo

// Inputs

#define I1 36 // PIN 4
#define I2 37 // PIN 5
#define I3 38 // PIN 6
#define I4 39 // PIN 7
#define I5 34 // PIN 8
#define I6 35 // PIN 9
#define I7 12 // PIN 16
#define I8 13 // PIN 17

// Outputs

#define Q1 23 // PIN 27
#define Q2 2 // PIN 29
#define Q3 17 // PIN 35

void logo(){
Heltec.display -> clear();
Heltec.display -> drawXbm(0,5,logo_width,logo_height,(const unsigned char *)logo_bits);
Heltec.display -> display();
}

void setup()
{
Heltec.begin(true /DisplayEnable Enable/, false /LoRa Enable/, true /Serial Enable/, false /LoRa use PABOOST/, 868E6 /LoRa RF working band/);
Serial.begin(9600);
// Inputdefinition

pinMode(I1, INPUT_PULLUP);
pinMode(I2, INPUT_PULLUP);
pinMode(I3, INPUT_PULLUP);
pinMode(I4, INPUT_PULLUP);
pinMode(I5, INPUT_PULLUP);
pinMode(I6, INPUT_PULLUP);
pinMode(I7, INPUT);
pinMode(I8, INPUT);

When I connect Port 36 (ADC1_0) with GND, then the Port 37 (ADC1_1) goes LOW for a short time (maybe 0,5s) too.

When I connect Port 37 (ADC1_1) with GND then the Port 36 (ADC1_0) goes LOW for a short time (maybe 0,5s) too.

The same Problem with Ports 38 and 39.

In the Pinout Diagram I see this notice: *ADC preamplifier
is this the Problem?

Thank for your Answer.

Greetings

Martin