That is a ISP issue not a browser issue.

''<p>ATRSunrise [[#question-1506660|said]]</p>'' <blockquote>My IP Address is changing automatically causing issues with online banking. Does Mozilla Firefox automatically change my IP address? Thank you! </blockquote> It sounds like your IP may be dynamic as your device gets a new address every time it connects though a cable ISP modem may likely only change IP if your modem is say powered off for a while for some hours like during a power outage. If your modem has the same IP when the device connects each time then it is likely static. Web browsers do not change your IP, though you can change your IP with a proxy or by using a VPN.