Hmm, it seems you might have a security setting in the Brave browser that's causing your settings to be deleted. Generally, Hivesigner works as expected: you enter your keys once. It also functions well when switching between multiple accounts.
There used to be an extremely annoying issue with Hivesigner - a checkbox for saving keys was checked by default. This caused issues whenever people tried to use a password manager, as it would attempt to save the keys and prompt users to enter an additional password.
Recently, they've updated the system so that the checkbox is unchecked by default, and now password managers work smoothly.