It's new in v1.12.x
if you don't like it. You can remove it in CSS
go to /admin/appearance/customise
add this
.composer .title-container .quick-search-results { display: none!important; }save and check if it's good.
I cannot delete my own topic (this).. when I click on the delete link, it appears a gray rectangle that covers all the page without the possibility to click in the modal window, bug?
Yeah most likely a bug. Think its fixed on master though. Just may not have updated here.