Might be related to the forcing of secure HTTPS connections.
If you venture into the following, there are risks that you might screw up — so write down careful notes about your every step. Be familiar with the instructions, first.
Info to study at
How to clear HSTS settings (in most popular browsers):
Example of something similar to what you have encountered:
Unfortunately, some HSTS settings can inadvertently cause browser errors. For instance, if you’re using Chrome, you might run into:
Privacy error: Your connection is not private
If / when you dare to venture - at your own risk:
Where the (how to clear) instructions mention, for example:
in the following line:
- Navigate to chrome://net-internals/#hsts
Using your Brave Browser, you would instead “Navigate to”:
There, are two sections re the instructions: