Are you perhaps confusing your LAN IP address for your WAN IP address? Your LAN IP is unlikely to change, since it is the address your computer uses to communicate with your router.
Your WAN IP is the one that needs to change, since that is the IP your router uses for accessing the internet.
LAN IP does not normally pass through the router to the internet domain.
Keep in mind that there are often many internal IP addresses in a network even when there is no connection to the internet. My computers each have a minimum of 7 IP addresses for internal hardware. Those are not internet IP addresses. They stay within my Local Area Network.
Test it: Do whatever you do to change your IP. Then go to IPBurger dot com. See what it says. Then change your IP again and connect to IPBurger one more time. If it changes, you're fine. If it doesn't, you need to correct that.
Don't manually compare your IPs from within your PC. You'll likely confuse yourself if you didn't know about the difference between LAN and WAN.
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