@nlindin This one works!

#include <M5Core2.h>
#include <IRremote.h>

IRrecv irrecv(35);
decode_results ircode;

void setup() {
M5.begin();
irrecv.enableIRIn();
}

void loop()
{
if (irrecv.decode(&ircode))
{
Serial.println(ircode.value, HEX);
delay(100);
irrecv.resume();
}
m5.update();
}

@ajb2k3 The IR in the GoPlus2 gives this by the serial monitor. Any updates?
Thank you and happy 2021.
E (42353) rmt: rmt_write_items(797): RMT PARAM LEN ERROR
send done
76
recv done
76
.
.
.

Hi!
Board settings==board info?

Whit "M5Stack-Core-Esp32"> M5Stack Arduino> M5Stack-Core2 works nice to me.

Thank you!

Hi!
Please, just to confirm... If we stack Core2+GoPlus2+M5GO2... We need to remove the battery from GoPlus2... Is this correct?

And another one... If we plug a 9v battery to the goplus2 DC-in, is there something special to adjust in the code or it auto detects it?
Have a nice day and thank you!

Hi again!
For now I have changed the .ino from GPIO 5 to GPIO 33, (35 is the same for both, Stack and Core2) but the ir receiver gives only "PARAM LEN ERROR" from all my remotes and buttons. I continue doing something wrong with the Core2+Goplus 2.
Any help, please?
Thank you!

@ajb2k3 Thank you for your answer. I want to say an example in arduino for Core2+Goplus2. With Uiflow it seems to work fine. With Arduino I am totally stuck in this scenario.

@m5stack Hi! Could you please put an example? I can not find a valid one. For example, how can we -using arduino- mix Core2 and GoPlus2 module? The example does not work. Thank you very much!