"Create WAN Port" Error while Port Forwarding on IPv4

Greetings,

I used to have a virtual server on the communication platform Teamspeak 3 which required me to port forward port 9987. It was on a Huawei router, I don't remember the model, I received it from the provider.

I port forwarded it without any problems but recently I changed my Internet Provider to Orange and they gave me a new router of model HG8245W5.

I was glad because I already knew the environment in which I'll have to port forward again for the server.

Once I filled in all the required settings and rules in the port mapping tab and went to apply the rule, I got an error: Create a WAN Port First. Later I noticed that setting WAN name wasn't set up automatically as it was in the previous router. I tried to open the selection tab that supposed to pop up but it seems I can't, it doesn't open or contains anything. I checked of WAN tab and there are 2 WANs. An IPv6 and IPv4 WANs. The IPv4 one is greyed out but enabled. I am unable to do anything else on the WAN tab besides checking on those two WANs. I can't add or change them. Everything is grey.

I tried the IPv6 tab, noticed the same Port mapping configuration tool, and opened the ports on IPv6. It works but it seems people whose provider doesn't use IPv6 are unable to connect. Meaning 2 out of 11 people were able to join.

TL:DR: I cannot open IPv4 ports due to "create WAN port first" error. IPv6 works fine but only particular users can join the virtual server, WAN tab is all greyed out, I can only see the in each WAN, not change them.

Thanks for your help.