BuddyPress.org

Deactivate loco translate and redo what i described previously.
Search also for evtl. issues mentionned on loco translate support.

Aside there is no reason to use that plugin if you don’t translated scecificcally BuddyPress to your nedd. sv_SE.po/mo are loaded automatically.
If despite this, you use your own translation version, see how to prevent your translation to be overidden. It’s explained in one of the sticky topics on the plugin support.