SFTP Timeout on reply request

[gp84-dot]

Hi SFTPGO community,

I got a strange behavior that i want to share with you.

I have several workload on Azure Datafabric that use my sftpgo server.

On theses workload i have this error message on sftpgo log side :

{"level":"debug","time":"2024-09-30T16:05:56.384","sender":"sftpd","message":"failed to accept an incoming connection from ip \"54.229.198.100\": read tcp 10.248.250.10:2022->54.229.198.100:24962: i/o timeout"}
{"level":"debug","time":"2024-09-30T16:05:56.384","sender":"connection_failed","client_ip":"54.229.198.100","username":"","login_type":"no_auth_tried","protocol":"SSH","error":"read tcp 10.248.250.10:2022->54.229.198.100:24962: i/o timeout"}

The strange issue is , this request is normally implicit

54.229.198.100 => my public ip NAT => 10.248.250.10:2022
This is explicit in my firewall and open

The return flow is normally implicit :
10.248.250.10:2022 => 54.229.198.100:24962

This flow was also open for out in my firewall but i got again theses error message.

Anyone got theses type of error ?

I have no idea why ...

The issue is not present with a simple sftp server (linux ssh with no sheel)

Many Thanks for your help and sorry for my bad bad english ....