Why does sometimes selfbumping work and sometimes it doesn't?

>>420614
If you bump a thread, you can't bump it again for some period of time unless someone else posts in the thread after your bump.

>>420614
The OP can't bump his own thread, or at least you have to wait a long time (like 5 or 10 minutes) for your post to be able to bump the thread again.

There might be other unwritten rules on top of that.

>>420618
>The OP can't bump his own thread

Sometimes it works and you don't even have to wait any time. But sometimes it doesn't. I don't know what's up with that.