All Google apps are unusable

By ‘Google apps’ I figure you mean things like Docs, Sheets, Drive, etc.? What about Gmail, same thing?

What Linux OS/distro?

What version of Brave is it? How did you install it?

Do you have any extensions installed/enabled? If so, does it still happen with them all disabled?

Does the issue occur in a Private window?

Does the issue occur if you create a new profile and try it in that profile? (Make sure your original profile does not have any open windows; only the new profile should be open.)

Are you using ‘Secure DNS’ settings in Brave? What if you turn it off?

Is anything set in brave://flags ? (Anything with a non-default setting will be sorted to the top, and will have a blue dot next to it.)