It hadn't occurred to me until I saw it at a large font size on another computer today that the @ in Fira Code (and some other font I have, I think) is actually like that, with the tail not going all the way around, on purpose. I always just assumed the bottom and left of the glyph were getting cut off because of some font rendering issue, but no, it's obviously meant to stop there, and this way the rest of it can be bigger. Seeing it as a design decision (even if one I think I don't prefer) instead of a bug makes the font so much more tolerable to use to my horrible brain! Nice.