Changing or changed IPV4 ip adress is normall especially you have an router assigning ip adresses to clients.
Do you know that your ‘localhost’ js you loopback same as 127.0.0.1. Windows have them in host file. Where in not especting ALL to bee the issue in.
Becouse i waited 2 days for someone else to respond!
**First of all **
Your FX Server had .cfg the default one i geuss, on the top you see an 0.0.0.0:XXXX addres **You will not need to change it in anything keep it at it! Only the XXXX port value you change!
This is for advanced settings!
Make that sure, in recommand an default server.cfg to solve it!
This XXXX port value you port forward TCP/UCP To the IPV4 adress in your router.
Also i think your issue is really easy, but nobody reaponded so i want to know now haha!!
Your FIREWALL, disable it completely and test! It it was the issue make rules in your Windows : Advanced Firewall Settings
Goodluck! And i espect an answer