I am Currently Experiencing some media file upload issues with WordPress within pages or posts.
Adding media in the media section does not have this problem.
Troubleshooting the Console shows some javascript being blocked though. Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
This error is common but it can be caused by more than one issue. If you are using Chrome or FireFox it can be due to the extensions. Therefore try disabling all browser extensions or try form a different browser/PC.
If you have an AdBlocker or Anti-virus software it may also cause that. Therefore try from a different PC.
If you are using a CDN service or caching, that can also be a common issue. Consulting with the CDN provider should help.
Also consult with your hosting provider, it is possible that they have certain restrictions as well.
