Forum New posts keep inserting thread title above post
 

In the last few days, often when a user posts in an existing thread, the threat title is inserted in the post too (they aren't doing it themselves). See here for example. Any idea how do I stop this please?

Note: maybe around the same time it started, I updated the forum counters for threads and then forums (I changed the global ignore option), but can't say for sure that there aren't examples from before I did this.

Thanks.