Google Analytics tracking code is async and you should update
I have been loading Google Analytics scripts async on my web properties since the async attribute was introduced. I honestly do not see any reason to prioritize analytics code versus my own content, because in the end the same metrics will be collected. Regardless if Google Analytics scripts are loaded sooner or later.
Guess what? Google thinks the same way and updated their Google Analytics tracking code to load analytics script async by default. If you have not already, you should immediately update your Google Analytics tracking code with the async property. This will help to avoid 3rd party script loading from blocking rendering of your mobile website content and help to provide a better experience for your end-users.
How to get the new tracking code version
Go to Google Analytics -> Property -> Tracking Info -> Tracking Code and copy paste the new tracking code snippet.