Does GW1 require a separate account from ANet/GW2?

Been using the same ANet account for GW2 since 2014. I bought GW1 Reforged today via Steam, but every time I enter my credentials I'm told the "The email "" doesn't exist" (doesn't include my email between the quotes, which is odd, or that my password is wrong. I double checked my password and email and both are correct, it just won't accept them.

Is it a separate account? Should I just create a new one via my Steam creds?