Yesterday, I did a post that if you have less than a 10% bounce rate, you are using more than one tracking ID of Google Analytics without knowing yourself.

People didn't believe in me.

I checked a site of a person who has a 7% bounce rate, and he was saying he is using one time. When I checked the site with its source code, he was using 4 times.

It has happened to me also.

Proof 1: https://moz.com/community/q/less-than-7-bounce-rate

Proof 2: https://www.en.advertisercommunity.com/t5/Google-Analytics-Reports/Bounce-rate-is-less-than-0-5/td-p/561445# (Answer of Top-Rated Carlos Escalera)

Proof 3: https://upsidebusiness.com/blog/my-website-bounce-rate-is-5-is-that-too-low-is-it-too-good-to-be-true/

Proof 4: https://www.techwyse.com/blog/website-analytics/improving-website-bounce-rates/

But you can check?

Easily! You will have a code like this: UA-4303302-3

Go to your site, and go to source code, and Ctrl+F, and paste your code between dashes, in this case, 4303302

What are the reasons?

It is common on Bloggers.

When you place the tracking ID in Layout, also in Bloggers' Setting Google Analytics and also within <head>.

The same case can happen to Wordpress when you put the code in the theme built-in panel, plugin and <head> manually.