No, the three way connection esrablishment on your web server looks good, but the Python code delays the syn ack unbearably wrong on both port 1001 and 80. the tcp syn “retransmission” and connection reset (initiated by freertos!!!) are NOT the same problem and may simply be consistent with the control flow. Wireshak may erratically see the next connection establishment after a connection shutdown as a retransmission.