issue with showing

[TomasBalbinder]

Hello, I use the Chrome web browser and sometimes when I refresh the page it happened this on pictures but after refreshing the page it's okay.
But when I use different web browsers like IE or Firefox issue the problem still persists.
Anyone helps me where can be the problem?

This is my web app, after registration, you have to create tasks and shows and there is a problem.
https://assignment-book1.onrender.com

link on Github:
https://github.com/TomasBalbinder/Assignment-book/blob/main/ToDoApp/templates/ToDoApp/show_posts.html