I really can't tell the reason for this. I only just joined the platform and haven't used the feed area yet.

One answer i can give though is that it might be that some peeps used the tag they aren't supposed to use.

let's say for example, I asked about food but included money as a tag, when you click on the feed for money the post on food will appear because the tag was used in the post.

So, i think users should be more careful to use only tags relating to the questions they asked.

I hope this helps!