I did all updates, before I post a bug here.
I think I found reason for this, was the plugin discourse-placeholder-theme-component cause JS error.
The fixing of this link MD Composer extras - #64 by Arkshine fixed my issue.
The reason for our instance has this issue was because our server hade issue to connect GitHub and cause this plugin didn’t update onetime.
We forked GitHub - discourse/discourse-placeholder-theme-component: discourse-placeholder-theme-component to different Git Service and re-pull all code to our instance then issue fixed.