Oc images tend to get less upvotes and faves than canon characters, that much is true. And yes, some may go stagnant. That’s an unfortunate fact. There isn’t always a specific reason and I certainly doubt it’s because people dislike your ocs.
It could have been due to the time you posted (less people being online), it could be due to spam posting from other s burying your image, it could be something else caught their attention, it could be that they weren’t logged in and couldn’t upvote, for example.
I would recommend not worrying too much about what gets the most upvotes and what doesn’t. Sure, upvotes and faves are nice, but in the end of the day, it’s all digital points with no actual impact. Draw for yourself, draw what you like and keep improving and evolving your art.
