Why am I seeing RST, ACK Errors?

edit

I'm seeing RST, ACK Error from IP: 172.20.1.77(Source) from port 22 to 22834 IP: 122.55.100.244(Destination), can anyone identify what would be the cause of this kind of error? Thanks.

I'm connecting to the destination using SFTP.

It seems the port is not consistent because it changes. When the port changes, for example from source port 22 to destination 52245, it will have a successful connection. But sometimes 52245 also gets the RST, ACK error and it will change to another port.