Arduino UNO with SIM7600

I am using the Arduino UNO for monitoring holiday houses (AC, water leaks etc)

Until now I used G GSM shields Elcrow from DF) without any problems
With the just bought SIM7600 shield I do have problems with the communication with the board.
I do get rubbisch as answer: 
          GSM is not Ready : 
          AT+CSTCC⸮⸮⸮⸮T'⸮⸮b⸮⸮j

          or

          incoming 
          +CMT: "+32495592615","","23/`3/29,09:41:57+08"
          Sta⸮us  

I tried to change the speeds to lower than 115200 Bd but then I do not get only ????????????? answers

Can anybody help me out with this

this is the basic test code to check communication

#include <SoftwareSerial.h>
SoftwareSerial myserial(2, 3); //used  extra wiring to connect RX and TX to pin 2 and 3
void setup()
{
 myserial.begin(115200); //Initialize virtual serial port 
 Serial.begin(19200); //Initialize Arduino default serial port
 delay(1000);