BuddyPress.org

@retroriff – in your second post, you mentioned you followed the BP codex where you placed define bp site via “Specifically, you can do this by creating a file called “bp-custom.php” in your “/wp-content/plugins/” directory (if you haven’t already).”

I would suggest that you delete the code you placed in bp-custom.php and add the code in wp-config.php per my post (ref: https://codex.buddypress.org/how-to-guides/changing-internal-configuration-settings/) – it works.