Actually, it just happened again while trying to mention in a regular thread.

@Elitre The issue looks familiar and scrolling up is really annoying. Unfortunately, I do not have such combination (Win 10 and Chrome) to test. In Win 7 with Chrome/FF/IE - it does not seem to be present.

If it's not too much trouble, please provide the following info

• do the same in a different browser?
• you were do Mention just by clicking on Mention icon or entering, e.g. [[ in VE?
• did you do Mention to a topic that was way down the Flow board?

Hey! Will try and replicate when I can, thanks for your questions.

I'm on https://www.mediawiki.org/w/index.php?title=Topic:Tjtgdywj6xjitlom&topic_showPostId=tjuokar5lf5tka49&fromnotif=1#flow-post-tjuokar5lf5tka49 now

1. opening the same page in Opera seems to work just fine
2. Mention button
3. It's the one on top, currently (but it's also the only one displayed in my window, because I reached it via link in email.)

Thx @Elitre! Will follow up with triaging and more testing.

It seems like a very specific bug - looks fine in Win 8 with Chrome 54/IE11. I haven't tried it in Win10 though.

Re-checked the reported issue in Saucelab with Win10 and Chrome (from 55 to 53) with betalabs and mediawiki - did not see the behavior described in the ticket.

Maybe I should post the console messages next time it happens.

@Etonkovidova , my notes say you will Triage this. Please put it where you think it goes.

@Elitre - the problem is that I saw the issue some time ago (couple of times) - but I could not reproduce it. Please, if you see it again, if possible, can you make a screen recording?

@jmattazoni I removed 'Untriaged' sttus, but I keep it in Flow in case that there will be more info on it or I'd see similar cases.