What URL are you using as a bookmark? What thread title are you prompted to edit?
I'm using Chrome and right click | Open in new tab opens the page normally. What browser addons are you running. Does it happen in a different browser?Doesn't really have anything to do with being a bookmark. Simple way to repro: if you open one of those URLs as a right click | Open in new tab, you'll notice that the edit box above the posts (that has the "Thread Title" hint in it) expands once you activate the tab and takes up the whole screen.
No, I can't replicate it on any device even logging in as a regular user. A couple users have reported something similar and the dev team is trying to find what's unique about their setups. 99% of users won't see what you do.Very weird why you don't see that. You have a wheel mouse I assume? Try wheel click on the link and give it a few seconds to finish loading in the background before you switch tabs.
Maybe you aren't seeing it because you're an admin and you have different stuff on your screen?