Tab focus not always present

When navigating PleromaFE using just the keyboard with tab, focus is not always apparent. It does come back, but it is apparently somewhat difficult to track visually. This also affects screen reader users, because there are some buttons that appear to not be labeled, but when I asked which button I had focused, there was nothing visually there either. I wonder if some of these buttons are missing aria-hidden? Most of where I tested and where this occurs is around the form for posting, after the subject field, and some after the actual post entry box.

There are 2 after the emoji button for the subject box, and also 2 after the "Just landed in L.A. post entry box.