FTP connection with multi-wan and Squid

[goodspeed_11]

Hi at all,

I'm sorry but I don't find solution to my problem..
I have a LAN network behind a fpsense proxy. I have a multi WAN with two modems and squid for the cache.

When I log on a serveur with filezilla, I connection is OK but after some second, I lost the connection and have a error message :
The data connection could not be established: ECONNREFUSED - Connection refused by server

What firewall NAT / rules must I do to resolve this ?

Thanks

[heper]

are you loadbalancing?

[goodspeed_11]

Yes, that's it

[Musli18]

how to you fix this problem?

[doktornotor]

Stop load-ballancing FTP.

[Musli18]

Can you explain it with more Details Please?

[doktornotor]

Set up FTP to go out via a single gateway.

[Musli18]

you mean i should add a Rule under LAN with following settings

Protocol    Source      Port    Destination    Port    Gateway

Ipv4          LAN net      any    any              21      WAN1

but is not working