Q: Why Instagram restrict my photos from liking?
A: It's still unclear why Instagram restricts likes. We guess it's based on how many strangers (i.e. not your followers) like your photos. If it's too many people like your photo, Instagram becomes unhappy and imposes the restriction.
To check whether you're restricted, you can try to like your own photo with the official Instagram app. The like will become un-liked if you're restricted. You can simply wait for some time, Instagram will lift the restriction within several hours.