I am experiencing a weird emoji picker placement issue.
Selecting the emoji picker via the toolbar works.
Selecting the “more” link on a new topic entry after entering a “:” works.
Selecting the “more” link on a reply post after entering a “:” the picker does not appear.
Quick video:
Suggestions on what to look for.
Maybe other topics about the same issue and their replies? 
But that’s not really the same thing? One’s about the wrong place, and one is not showing at all. It could be related, of course.
In the other topic the modal appears much further down. I assume that this is simply not visible at all in this example. Seems it depends on your scrolling position. It’s invisible if you are at the bottom of the topic and allows you to scroll down infinitely. But I think once the positioning is fixed, this won’t happen anymore.