Jquery was not loaded when posts have youtube video link

Hi everyone!
I have a problem. When I tried to add a youtube video link in a post, then I have error $ is not defined.
I searched, and check network also and I saw: jquery-1.12.4.min.js file was not loaded if one post has youtube video url.
So, how can I resolve this problem?
Please help.
Thank you so much!

Do you have the same problem on try.discourse.org?