Huge Analytics discrepancy when I turned off Analytics Module & Turned on GA via GTM

[JJLWeber]

Hello,

I was running universal GA via a GA Drupal module. We setup Google Tag Manager and setup a GA tag to run through GTM. When we pushed the GTM container live our Real Time was at around 1900 and when we turned off the Drupal module the Real Time was reporting around 1100.

After 24 hours the sessions for that day were about 100k lower than what they usually are.

Any ideas Why the larger discrepancy? Any places that are obvious to look?

*I didn't setup the original Drupal GA module, nor do I know who did.

Thanks

[JJLWeber]

Thanks, Dirk. I had the devs move the data layer above the GTM container snippet. The GA tag is still not firing on pages with a data layer and firing on pages without a data layer.

Obviously, it looks like there is an issue with the data layer -- I can't figure out what it is. I took a screen grab of the data layer in the source code.

4mliOJP

[DirkC]

Can only give you a theoretical answer - don't have that much experience with debugging the tag manager. From the "manual":

Data layer needs to be above the container snippet
Datalayer should be added above the container snippet. Variables pushed to the data layer after the container snippet will not be able to fire tags on page loads with a matching condition.
Variables pushed to the data layer after the container snippet will not be able to fire tags on page loads with a matching condition.
Move the datalayer to above the container snippet

Check also https://www.optimizesmart.com/google-tag-manager-data-layer-explained-like-never/ - it seems that you define your data layer after the position of the tag - so the tag cannot send the info from the data layer to Analytics. Check your source code & check where the data layer is defined. Probably it's ok on your category pages but not on the detail pages (compare both types to see the difference)

Hope this helps.

Dirk

[JJLWeber]

Hey Dirk,

I checked the debugger and on the pages where the tag isn't firing the console isn't even acknowledging GTM.

The Tag Assistant is showing this error on pages where the GA tag is not firing: 'data layer needs to be above the container snippet.'  Do you think this could be the issue?

I work with a journal site, and I notice that on landing pages the GA tag mostly fires correctly, but on article pages the tag doesn't fire and I get the 'data layer' error from tag assistant. e.x: the tag fires on /news but not on /news/some-random-article-from-today

[DirkC]

Apart from the Tag manager assistant - you could also check the debugger -https://chrome.google.com/webstore/detail/google-analytics-debugger/jnkmfdileelhofjcijamephohjechhna?hl=en-US  - like Martijn mentioned there should be an error somewhere - did you check the messages in the console?

[JJLWeber]

That is possible, the coding is a mess. How could I see if there were or were not JavaScript errors on the page? And if there were, how to pinpoint which are interfering with my GA tag firing?

Thanks, Martijn!

[Martijn_Scheijbeler]

Are you sure that there are no JavaScript errors on the page?

[JJLWeber]

I found a subdirectory that the GA tag is not firing on though the GTM container is present.

When I use Debug, I get this message:

No tags were evaluated because there was no Event in the selected Message

I have no idea as to why the tag is not firing.

[Martijn_Scheijbeler]

Hmm yeah that seems right to me!

[JJLWeber]

Thanks, Dirk. I'm going to follow your suggestions.

Martijn, the track type id is 'pageview' and is set to fire on 'all pages'. For my Tag Firing Options I have selected 'once per event.'

Does that seem to be right?

[Martijn_Scheijbeler]

What Dirk is suggesting would be the first thing to do in my opinion as well. But the second one is what trigger are you using in Google Tag Manager. Are you targeting all pages in there or something else?

[DirkC]

Run Screaming Frog - and check if the tag id is present on all pages. Apart from checking - you could also extract the code from the source to double check that the ID is correct; check here how you can do this

In Analytics reporting (Behavior > Site Content > Content Drill down) set the day after migration & compare it to the day before migration - check if there if the drop is generic (=all pages) or linked to a few sections. If the drop is higher in specific sections - go down to next level & do the same. Check the pages with the highest traffic loss using the Tag Assistant plugin for Chrome. It checks if the tag is properly implemented on these pages (https://chrome.google.com/webstore/detail/tag-assistant-by-google/kejbdjndbnbjgmefkgdddjlbokphdefk)

You can also use the Tag Assistant plugin on your main pages to see if it is sending data as you would expect.

Hope this helps.

Dirk