Recently linked my Steam account so I can buy some DLC through Steam, went to join a raid with some friends and was told I needed to verify my account through SMS, tried that and got the error "We’ve encountered an error, please try again later. (3)".
I've tried multiple phone numbers, multiple devices, multiple browsers, accepted cookies (as others said is required), tried a VPN, tried 4G on two different networks, literally tried everything that I possibly can and still get this error. I've had the error for days now. :(