Passive FTP
Passive ports are used to allow multiple FTP connctions by moving open FTP connections from port 21 to a port specified in the passive port range (40,000-40,100 standard UKFast passive port range
Check in /etc/proftpd.d/passive ports folder
Can connect but can't retrieve directory listing:
80,244,185,220,156,149
First 4 numbers are the server IP,
Multiply 5th number by 256 = x
X+6th number = passive port which is being used
156x256=39936+149=40085