Railway authenticates through external providers (GitHub, Google, email), and support cannot change or swap the login identity on an account. This is a security boundary that protects your account, not a policy limitation. Signing in with the new email creates a separate account because it is not linked to your existing Hobby account. To get back into your Hobby account, sign in with the original login method (the email, GitHub, or Google you used when you first created it). If you no longer have access to that original provider, you would need to recover it on the provider's side first, and then your Railway login will work again.