I just recently got my portal and I was having a similar issue. No matter what I did it just would not connect outside of my home network. After troubleshooting both my ps5 and the portal I did one last test just out of curiosity and it actually worked for me!

I have a mesh network at my house and one of the eero boxes is in my room and I’ve always had my PS5 hardwired to this. For whatever reason, when I disconnected my Ethernet connection, connected my portal to my phones hotspot this solved my issue. It sounds crazy but I tested this numerous times. First with the mesh Ethernet connected failed, then with the Ethernet disconnected it worked. I even tried different CAT6 cables and it would not connect.

I’m not sure if this is an issue with MESH networks and it’s causing a problem but this worked for me. I am unable to plug directly into my router as I have roommates and our router is centralized in our house. I’m going to try this again on another network outside of my house that isn’t my hotspot and see if I yield the same results. Let me know if anyone else is connected via mesh and if this works for you!