My friends get disconnected to my Minecraft server

I am deeply sorry to post this silly question but here is my problem:
Recently I made my mc server, I port-forwarded the 25565 port and my friends joined and the server worked perfectly. Then all of a sudden, they disconnected all at once. After some investigation I realized that my external ip adress had changed. I kept giving my friends the new ip adresses every time they changed but that seemed like not the best solution. Also I checked and my ips are static. I have some screenshots containing the problems and info here.
Capture.PNG Capture2.PNGI used PortForward Network Utilities to make the ips static and every one is static and the external ip keeps changing. Is there a way to stop the external ip from changing or no?
P.s. DHCP is not enabled on LAN.
Sry for my derpy tech language if you don't understand anything just ask :D
 
Okay, that is a legit issue. Your external IP address is provided by your Internet Service Provider. It seems as if they either have it set to switch IP addresses constantly, or they're doing that just to you to prevent you using a server unless you pay more money for a static IP. My local provider refreshes my IP very rarely, but I have had it happen in the past and it did confuse me for a bit. Call up your ISP about the problem, and see if you can figure out a way to stop it. I wouldn't imagine it adding too much more to your internet bill, but I honestly don't know.
 
What u are on has nothing to do with having a static IP Address from u'r internet Provider (ISP).
 
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