I had a problem where I often couldn’t join multiplayer games or friends’ lobbies, but other people could still join my friend without any issues.

After testing, I found out the issue was related to NAT type on my network.

Problem

• Symmetric NAT on Huawei router
• Steam P2P games like Teardown not connecting properly
• Random ability to join games, very inconsistent
• Others could join the host, but I couldn’t reliably connect

What fixed it for me

In my case I had Symmetric NAT on a Huawei router, which caused issues with Steam P2P games (Teardown in my case).

Steps I took:

1 Checked NAT type in router (was Symmetric NAT)

2 Changed network/IPv4 settings in router (Huawei settings / ISP configuration

(sometimes if you dont have IPv4 enabled the net setings won't show up)

3 After the change, NAT type became Asymmetric

4 Restarted router and Steam

if you have any problems along way be free to ask