M5CoreInk Serial2 Issue I don't understand

[HappyUser]

Dear all, I am using dsmr.h te read out my smart meter at home. Reading is done through Serial2. Just as in the dsmr example, the declaration of the reader is like this :
#define RX_PIN 13 // read
#define TX_PIN 14 // Transmit
#define Read_PIN 26 //33 //23
P1Reader reader(&Serial2, Read_PIN);
On my M5Core2 reading out the serial2 interface with above setting works great. Now I have transported the software to M5CoreInk. Same cable, same pin settings. I don't see any readings anymore. So I checked in a simple loop while(Serial2.available())
{
int ch = Serial2.read();
Serial.write(ch);
}
to see if any data is coming in. And I see on my terminal that the data is exactly what I suspect.
Now my question is, is there something with Serial2 that works differently on M5CoreInk than on M5Core2 that somehow effects the dsmr constructs using P1Reader reader(&Serial2, Read_PIN);
The software works on M5Core2, on M5CoreInk the data is coming in, but suddenly not anymore using this reader construct. Any suggestions?

[HappyUser]

Oh I forgot, and this is how the Serial2 is initiated (MrCore2 and M5CoreInk) : Serial2.begin(115200, SERIAL_8N1, RX_PIN, TX_PIN,true); // Serial2.begin(9600, SERIAL_8N1, RX_PIN, TX_PIN); //Serial port 2 initialization
delay(300);