Doh! I had a detailed reply about the Borderlands website issue, but it didn’t work through email, and now I can’t find that message.
Using https://borderlands.com/en-US/vip-activities/ as an example (after logging in), none of the activities would display. Looking at the HTML showed those activities are loaded from crowdtwist.com, which probably hosts a lot of things Brave shields would normally block. But even if I visited that domain and lowered the shields, things still wouldn’t work back on the Borderlands site.
This same issue showed up throughout the Borderlands site, wherever there was CrowdTwist functionality, like redeeming codes, claiming rewards, and earning points through activities.
I tried deactivating all my extensions. I tried an incognito window, I tried resetting Brave. Nothing worked until I follow those steps I shared above to toggle each option in the Shields pop-up.
After doing that, the Borderlands site behaved as expected, and then so did other sites, including TradeDoubler—even without doing anything further with my shields.
So it really seems like the shields’ global settings were corrupted, but toggling them fixed them.