Since installing Mac OS Sequoia Firefox does not start because of Firewall problem.

FWIW, I use Firefox 130.0.1 as my primary browser on three different Macs running Sequoia without issues.

Please install EtreCheck and post the report. Allow Full Disk Access.

https://etrecheck.com/

Use the Additional Text icon to paste in the report. Perhaps the issue may reveal itself.

This Reddit thread has some suggestions. They involve issuing Terminal commands to alter firewall settings.

Reddit – Firefox no longer works after upgrading to macOS Sequoia

There are some indications that firewall changes and/or other network stack changes may be causing issues with third-party security tools, so if you are running any of those, it may be helpful for you to tell us that.

AppleInsider – macOS Sequoia causing issues with third-party security tools and web browsers

macOS firewall is cosmetic to produce warm fuzzy feeling to some users, but it is not needed so just disable it ...in the past I used it (and wondered why it is off by default) but I am now convinced by more knowledgeable users that it is not necessary. I had no trouble with firewall but, just like you, a few years ago my son could not use some Wi-Fi before turning firewall off (sorry, I do not know more details).