Check the firmware for your router. Sometimes a new version of the software appears, e.g. after 3 years. In most cases, you manage of your router and not your ISP, so it is your responsibility to keep the software up-to-date. It is possible that you can do an easy update via OTA - that is, directly from the router's panel, with one or two clicks (first click on the upgrade button and the second click on accepting the selection). Here is example: https://www.youtube.com/watch?v=iaTUSFgxhU0 In the description of the new version of the software, see the changelog from the manufacturer - usually these are fixes, improvements and security patches, they can also be new functionalities. The update takes a few minutes and the router will reboot. The safest update is via an Ethernet cable plugged into the LAN port on your router (instead of WiFi). Remember to download the software from the manufacturer's website. Check your device model and hardware version (it will be visible on the device label on the bottom or after logging into the router panel in the router GUI). Remember to make a backup of your settings for safe.

If your software is old and you want newer software see OpenWrt (you can find information about this software on my channel).