[Defender Pro] DEFENDER Blocking all traffinc front-end and back-end

Hi,
our client notified me that they were fully locked out by defender. When i opened their site, i had the same issue, while my IP should be whitelisted.

When i rename the defender folder, i can get access to the site and dashboard again.
When activating defender, i’m lokced out again.

I’ve tried the add a whitelist script in the mu-plugins folder, but this has no success.
Where does Defender store the whitelisted IPs?
Buy the way, in the defender_lockout and defender_lockout_logs my ip isn’t listed

What tables is defender using so i can delete it manually and reinstall a clean / fresh version.

Regards,
Herre