Hey all,
We have some excellent connection troubleshooting steps in the links below. The basic connection troubleshooting link is a great place to start and the steps aren't overly complicated to perform. They fix most general connectivity problems for players.
If you know how to log into your router's admin panel (the instructions are usually on the router itself), log into it in order to enter in the selected ports for Apex Legends. Some routers may have specific ports closed off by manufacturer default or from an update.
While you're logged into the router, check to see if you need a firmware update. If there's an option to enable IPv6 in there too, switching that protocol may yield you better connectivity results too.
Basic Connection Troubleshooting
https://help.ea.com/en/help/faq/connection-troubleshooting-basic/
Port Forwarding
https://help.ea.com/en/help/faq/opening-tcp-or-udp-ports-for-connection-issues/