Default template, nmap modbus port ModbusInvalidMbapError-

[bestrocker221]

Describe the bug
A clear and concise description of what the bug is.
When doing an nmap scan towards conpot, nmap does not even recognize the modbus protocol because nothing get returned to it.

To Reproduce
nmap -sC -sV -p 502 localhost

Log
2022-07-09 18:00:06,565 Modbus ModbusInvalidMbapError: Response length is 11592 while receiving 8 bytes.

Problem seems in handle_request in slave_db at

slave_id, request_pdu = query.parse_request(request)

Cannot get further