We undertand how frustrating it is to be stuck in a vicous circle of log in attempts!
The suspicious login attempt and security code sent is not from us. They are a security feature and messages from Instagram themselves.
Firstly, please try logging into Plann one more time and when it sends you the code. DO NOT login.
Instead log into Instagram and wait until you receive a message from them asking you to confirm that it is you trying to log into Instagram on all devices and locations.
After you regain access to your Instagram account, then try logging back into Plann. We recommend waiting a little time before logging back in so that Instagram registers your confirmation.