BuddyPress.org

Not a single solution? really?

Have you honestly scoured all the docs pages here and the WP codex ones, have you searched the posts in the support groups here?

I know that this issue crops up often enough that there are many posts that have covered this aspect or issue, there is also WP
codex pages on permalinks and how to deal with them which essentially is the issue you are experiencing by the sound of things.

One last point this isn’t really a BP issue , it’s a WP one WP handles this aspect and it’s important to get WP working correctly before moving on to activating BP.