I encounter an error, people might be losing visits.
If we use the normal Tracking Code ID UA-XX
And adding the GTM code ID's
That way it will track the first visit when you enter the url but will not track when you start navigating.
If you use GTM code ID's alone, without Tracking Code ID UA-XX , the same thing will happen, no tracking when you start navigating.
But if you use Tracking Code ID UA-XX , only, without putting GTM id's , it will track all pages you are navigating.