keeps redirecting to in regular Brave window

For some weird reason, my Brave instance on Windows keeps redirecting urls to the homepage. This means I can’t login ( or view shared files (…), because those use the link. I have found some online conversations saying that I should use either Google’s or Cloudflare’s DNS, but that does not seem to fix it.

This occurs for me on a regular Brave browser, but not in a Private Window, and not in Google Chrome or Edge, so it looks like some setting that affects regular Brave windows is somehow affecting this. It seems to work fine on another Windows PC that has synced settings, and it also works fine using the Android Brave app, both on the same local network. Removing cookies does not fix it either.

Does anyone have any ideas on how to fix this?