bbPress.org

ok, if you can’t get the right sidebars to show, just have one sidebar and use widget logic to decide what widgets show in which pages

https://wordpress.org/plugins/widget-logic/

then for each widget there is a widget logic box

put

is_bbpress() if you want that wiodget to appear in forums
!is_bbpress if you want it to appear in pages other than forums
and leave blank for both