(Kerlink-iFemtoCell-evolution) "not connected" to TTN

Hi,
the status of my gateway in console is “not connected” as the picture below, but I do not know what the problem could be to fix that. I would greatly appreciate if someone could advise me in this regard. my gateway is Kerlink “Wirnet iFemtoCell-evolution”. I added gateway EUI as it is written under the gateway and also with the command cat /var/run/lora/gateway-id.toml .
before configuration I had done factory reset twice, is it possible that this made it changed?
I did Keros 4.3.3: CPF configuration as it is written in Kerlink website, and firmware version is Keros 4.3.3
Kerlink provides a packet forwarder (CPF)
I am using TTN V2, and there is no Data payload in my application side.

d587b87423d97fb0e087be51abd5b70f7072284f

I found other Kerlink users have had the same problem and they responded that “the problem is with firewall, and changing the /user/spf/bin/execute_spf.sh file and editing the IPTable by replacing all “-A” (append) options with a “-I” (insert) solved their problem”, but they used (SPF) semtech packet forwarder while I did Keros 4.3.3: (CPF) configuration as it is written in Kerlink website, and my firmware version is Keros 4.3.3.

I would appreciate if someone could advise me regarding these questions:

1) as there is no /user/spf/bin/execute_spf.sh file used in this version, which file I should open to edit the IPTable by replacing all “-A” (append) options by a “-I” (insert) for Keros 4.3.3 to connect TTN?

2) how I can do that using SSH. Can you tell me in details please?

3) For the future usage and connecting it to ChirpStack, if after changing this rule to -I , I do a factory reset and upgrade with liveburner IPK, will these changes I made revert back to the default?

See Kerlink iFemtocell - connect to TTN? - #35 by mari

Cross posts, so closing this new thread.