I experience this issue on Chrome and Safari as well (Desktop and Mobile). Most of the user avatars look normal but some are hidden, displayed like your screenshot or like this:
I don’t know if other people experience this as well but when I go to someones profile page on the forum there are no avatars shown next to their names at all.
Yeah, pretty sure that just shows the original poster.
The keyboard shortcuts list looks correct to me. You have to press M twice in a row to mute a topic. Same with setting it to Regular, Track, or Watch - you press M first, then another key to actually set it. Pressing M by itself doesn’t do anything. The “Jump To” shortcuts work the same way.
I’d like to add something to this list, in code fences in docs pages you can not select some text and right click. if you want to copy that right clicking on it deselects them.