MKR 1010 and A02YYUW Waterproof Ultrasonic Sensor

[horace]

@alexopth1512

  Serial.begin(19200);
  Serial1.begin(9600);

you reading bytes at 9600 baud and printing textual information at 19200baud
you are probably overrunning the Serial1 input buffers and loosing information
try

  Serial.begin(115200);
  Serial1.begin(9600);