Yes, this happens when you have used a meta description through code in your head section like in this website https://socialmediavideodownloader.com where i was using meta description through code then it was showing the same in all the pages as well as posts but now when i have removed the code it was showing different meta description in all the pages and post.
But some time it can be because of some plugin as well because when you use multiple plugin it overlaps each other and then error happens.