Broken Tracking with Matomo Tag Manager all of a sudden

We are using Matomo on a storyblok-website with tracking being set up using Matomo Tag Manager. However, since 30 March 2023 we are receiving almost no traffic (1-digit visitors) on our site as well as the sites of one of our customers.

In order to identify the source of the error we can provide the following information:

  • Matomo Tag Manager is correctly implemented and we can load third party scripts (such as Facebook, LinkedIn) successfully
  • Tags are executed, as has been tested using the Debug-Mode of the Tag Manager.
  • Both sites use Matomo Cloud.
  • Both our site and the customer-site use the storyblok-framework and integrate Matomo using the nuxt-matomo plugin (https://github.com/pimlie/nuxt-matomo).
  • We have made no changes to either the website or the tracking-setup on our end.

Has anyone else noticed these issues?

As we have made no changes to our site and this is happening on two sites we are fairly certain that the cause of the issue is an update to Matomo Tag Manager or Matomo itself, however we can find no information in the changelog that might cause this.