It’s hard to know what every troubleshooting step includes but here are a couple of ideas:
Some gmail users have stated that they couldn’t find the email in their inbox or in spam, but if they searched for it, they could find it.
Some ISPs (especially if you use their rented routers) block access to certain addresses and/or ports. For example, on Comcast support forums, you will often see people suggesting disabling “advanced security” when someone can’t reach some service or website. Another possibility is to try an alternate ISP such as a hotspot on your phone. Then after that, you can change your network setting back to normal (just change the network setting, don’t do a factory reset which would require activation again!)
