Hello.
I had issues in GA4 showing an unlikely high count of phone calls from desktop devices, so I decided to start sending data to Piwik Pro from that same instance of GTM, placed the whole container from Piwik in a GTM tag per the instructions.
After looking at Piwik reports I see the same weird counts, suggesting the issue may be happening in GTM (tripple checked triggers and look ok).
As next step I’d like to place Piwik independently (outside) from GTM.
Is it safe to deploy both snippets? what caution should I take? will the dataLayer be able to keep up with both TMS’s? should I create a dataLayer for each?
Thanks in advance.
R
Hi @dataindex,
There is no problem with using GTM/GA and Piwik PRO at the same time. The dataLayers of PP and GA can work together and it’s not necessary to seperate them 
Can I use Piwik PRO and Google Analytics at the same time? | Piwik PRO help center.
Thanks Adam.
ok then I’ll only use one dataLayer for both tag managers.
However, if you’re thinking of using both Google Tag Manager and Piwik PRO Tag Manager, it’s better to stick with just one
I want to benchmark GA4 vs Piwik as I’m seeing a very high count of phone calls from windows desktop (higher than phone calls from Iphone) in GA4. After triple checking triggers, next step to troubleshoot was to add Piwik tags to GTM and I’m seeing the same high counts. Next step would be to fire GA4 and Piwik independently and see the counts.
I’m currently firing GTM/GA and Piwik Pro from each WP plugins but unsure about what fires first or if it could become a problem. Looks like no issues but would be great to confirm about any potential race conditions and effect in counts or other conflicts as you mention in your article.