I use this feature almost every day. 
There is a chance I’ve had some kind of aneurysm, but I’m fairly confident that it should ‘reverse the bump’.
Hmm. 
We might be in aneurysm territory. Having a read around it does seem like what you’re saying is expected.
But I have distinct memories of using it to send topics that I’ve posted on back down the list.
I was so utterly convinced I was right on this, but I’ve spun up a stable test site and the same thing is happening there too. My bad. 
I’ve obviously gotten too comfortable with my workarounds and forgot how it really worked. How embarrassing. 