But it looks fine for me so have you got a browser/extension problem?
Might be useful to show us which site it isn’t working on as it’s fine here on meta.
If it works here, then Instagram has possibly blacklisted your server or IP range?
Just reporting anecdotally, we’ve seen some weird inconsistent Instagram oneboxing lately. A couple cases recently where we see the preview image failing to display and then a day later or something seems to work. This happened even for one of our own IG videos that we’d recently posted and displayed perfectly fine on instagram.com
I suspect there may just be some jankiness with the Instagram API unfortunately…