[_ck_]

You might have a plugin interfering with something?

What do you have installed?

Note there is a bug in the way the “front page topics” plugin works in how it changes the number of topics shown on the front page. It’s method affects other calculations incorrectly. I would almost bet that’s your problem. I posted a fix somewhere around here…

Here it is. Remove front-page-topics plugin and use this instead:

https://bbpress.org/forums/topic/custom-topics-count-for-different-pages-that-doesnt-break-last-post?replies=1#post-9796