@predrag thank you for your assistance, this has partly solved my issue.
I can now access the back-end again, but if I activate 2FA, without forcing it to the users, I’m not able to generate a QR code.
I installed Defender on another site, where it does work.
https://ibb.co/4ZtrXKv
Defender v 2.4.5
Wordpress Version 5.7.2
But on the current site I’m working on, it doesnt work.
https://ibb.co/LpvXXy3
Defender v 2.5.3
Wordpress Version 5.7.2