You should always troubleshoot the problems first before updating FW. Updating is most cases does not fix the issues and most issues are configuration or problems upstream from the router.
Things like ISP modems and line signals can effect how the router works. It's what most people look at first and the router in most cases is reporting just that, something is wrong and not necessarily something wrong with the router. Cable and DSL lines should be check and verified they are in good condition. For Cable, splitters are not recommended or at least kept to a minimum as they degrade signals unless they are amp'd. DSL lines should be filtered correctly and phone lines installed correctly.
Check the status of the ISP modem first always. You can most times review the logs of the modem to see if there are problems there. For DSL and now newer cable modem, have your ISP bridge the modems to the router. Most ISP modems come with a built in router and having 2 routers on the same network introduces possible connection problems. If you connect a external router, you'd want the ability to use all the features it has vs the ones that come on the ISP modems.
Then go to your router after that. Make sure any configurations are setup correctly. Use Static IP addressing to help manage and trouble shoot. Turn off features of the router that are not needed or used, things like WISH, Protected WiFi setup. Use QoS, Port Forwarding and Virtual Server options when needed. Gaming consoles should be setup for QoS. Gaming PCs should use Port Forwarding options.
Save off your configuration to file before doing resets. Saves you time if the problem is corrected and you want to reload your settings.
Always troubleshoot the issue first and then update FW as a last resort.