Hi there!

https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/comment-page-4/

Firefox shows an highlighted shield icon at the left end of the location/address bar in case Tracking Protection is blocking content.

• click the shield icon for more details and possibly disable the protection

You can check in the Web Console what content is blocked.

• "3-bar" menu button or Tools -> Web Developer
• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Hello phuonganhbui92,

You say that you haven't installed an ad blocker, nor do you see the shield icon at the left end of the address bar.

Could it be that you're using a content blocking add-on like Ghostery, NoScript, Privacy Badger ?

If so, would you please disable it (on that site) and see if that will make a difference ?

Are you possibly using Private Browsing mode as that may websites think you are using an ad-blocker ?

• https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history
• https://support.mozilla.org/en-US/kb/common-myths-about-private-browsing