Novatel OEMStar COM port

Continuing the discussion from Nmea gps px4:
Checked the work
nsh>serial_test -b 9600 -B -p /dev/ttyS2 -i 8 -t -R ascii

Error, count: 1950, expected 31, got 2c
Error, count: 1951, expected 2d, got 34
Error, count: 1952, expected 35, got 36
Error, count: 1953, expected 37, got 2e
Error, count: 1954, expected 2f, got 30
Error, count: 1955, expected 31, got 2c
Error, count: 1956, expected 2d, got 30
Error, count: 1958, expected 32, got 30
Error, count: 1959, expected 31, got 37
Stopped receiving.
/dev/ttyS2: count for this session: rx=1960, tx=0, rx err=1899

Incoming data is displayed correctly. How to debug errors? What does each error output column mean?

what is the output of gps status in the nuttx mavlink shell.
Also is the gps module connected to GPS2 port of the flight controller