Tag Manager Custom Event Trigger Not Working in Matomo 5.1.2

Support & Bugs
1

Hey Matomo folks,

I’m stuck with a custom event trigger in Matomo Tag Manager (5.1.2, self-hosted) that’s not firing right for form submits on my WordPress site. It works in debug mode, but in production, it misses about a third of the submissions.

Setup: Running Matomo 5.1.2 on Ubuntu 22.04 with PHP 8.2 and MySQL 8.0, tied to WordPress 6.7.1. I set up a trigger for a form_submit dataLayer event, but logs say “Trigger condition not met” even though the dataLayer push shows up in Chrome’s console.

What I Tried: Cleared caches, republished the container, tested in Edge, and checked dataLayer timing. No JS errors. I saw a 2024 thread about a similar issue, but no fix there.

Question: Has anyone got custom event triggers working smoothly in 5.1.2? Any settings I might’ve missed or debug tricks to try? Appreciate any pointers!

2

Hey @Alsi4576, I had a similar issue with Matomo Tag Manager 5.1.2 on WordPress.

The “Trigger condition not met” error often means the dataLayer push is too late for the trigger. Try this:

  1. In Tag Manager, edit your form_submit trigger and add a 100ms delay (under Advanced Settings > Trigger Delay).
  2. Ensure your form’s JS pushes to window._mtm before the submit event (e.g., window._mtm.push({'event': 'form_submit'});).
  3. Check if WordPress plugins (e.g., caching) minify JS, which can break dataLayer. Exclude Matomo’s container JS in your caching plugin settings.

Test in Preview/Debug mode again, then republish. This fixed my form tracking misses. Hope it helps!

3

Thanks for the detailed fix! I’ll try the 100ms delay, check my JS push, and exclude Matomo’s JS from caching. Will test in Debug mode and report back. Appreciate it! :blush: