So... I decided I'd try playing a match again, but I can't use my old player ID of 26 with it's key to login and if I try to setup a new account with my email, I get "Server error." Email is the same as the one for my forum account, Tom, if need it to figure out what's going on.
I believe I can answer your questions, as the same thing happened to me & I consulted with Tom regarding it:
1) Only part of the key is going through, which leads to it giving a false login password.
2) The server error is because you are using the same email (it would allow a different email).
3) Tom asked that I email him from my email account used for that game account, with the details of the issue. I'll message you the email that he directed me to email to.