I verified on my test site that it worked for new mappings. Perhaps there's an issue with the profile link being cached. Could you try the following:
1. Set JFBConnect > Configuration > 'Cache Duration' to 0.
2. On the front-end, log out and log back into with the LinkedIn user.
3. Check the link in the User Map area. Does it go to the 404? Could you inspect this link before clicking on it and let me know the value if it does go to the 404?
If the 404 still exists:
1. Keep the same user logged in on the front-end, but delete the mapping in the User Map area.
2. Enable the SCLogin > Logout View Settings > 'Show Connect Account Button(s)' setting.
3. On the front-end, connect the LinkedIn user to the currently logged in user (to not create a new user).
4. Log out on front-end, then log in again with the LinkedIn user.
5. Check the link in the User Map area. Does it go to the 404? Could you inspect this link before clicking on it and let me know the value if it does go to the 404?
-Melissa