Having the same problem. The weird thing is that gifs work perfectly fine in the original post of my devlog thread, but all my replies with gifs to that thread don't show the images. The gifs are all hosted on the same place (my website) and the BBCode is formatted the same way in the replies as it is in the original post, but still doesn't work. Same thing for me that it works in the preview, by the way.
Sorry for the double post, but I've found the reason why this is happening (to me at least). Gifs that have gone through size reduction on websites such as ezgif don't seem to display anymore on the new forums. I tried uploading a gif directly from a gif recorder with no problem but when I optimized and re-uploaded it, it stopped displaying, although it still displays in the post preview.
Yeah the cause of this as far as I can tell is that Xenforo uses its own image proxy thing to keep all assets, graphical or otherwise, transmitted via SSL. For some weird reason, that feature is barfing its brains out when it comes to embedded Giphy stuff, and it's on the list of known issues we're working through on the forums. It's working on non-Giphy gifs, which is sort of annoying, but a good workaround for now- https://forums.toucharcade.com/threads/posting-gifs-not-working.322177/
