BuddyPress.org

I can’t reproduce the problem you are describing.

In bp the title of a post going from bp group forums to bbpress goes through all the same filtering as the content except the following:

wpautop

make_clickable

bp_forums_filter_encode / bp_forums_filter_decode filters. The content gets that treatment.

Are your umlaut chars showing ok in bbpress if you enter them from bp forums?

Just to narrow things down. Can you temporarily comment out line 4 in bp-forums-filters.php which reads: add_filter( ‘bp_forums_new_post_text’, ‘bp_forums_filter_encode’ );

Then try adding a new post with umlaut chars. This filter needs to be there but let’s see if it is the problem.