Not sure if this is to be expected, but if you change your email address and then open DeltaChat, it will fail to login (that’s expected) but will continue to try and logging in endlessly with the wrong password in very short time delays.
In my opinion it should stop when failing for N attempts and wait for manual intervention.
How did you change the email address? Normally Delta Chat should not try to use new login and password if it never successfully finished reconfiguration.
I see how this can happen by changing the password on the server, but if login and password on the server is unchanged, then in Delta Chat it should not be possible to switch to the new configuration with invalid login/password pair.