Data collected from goals conversions does not match other data collected from form submissions

Hi there,
we collected some data from different campaigns and goal conversions and now we are trying to analyze them. Thing is, data from different sources don’t add up and I’m quite confused why.

We tracked the submissions of a form which at the end redirected the visitor to a thank you page. So we set up a goal that was triggered when visitors visited a given URL and the URL was exactly the thank you page URL (goal could only be converted once per visit).
Meanwhile every time a form was submitted the data were also stored in wordpress.

Logically speaking, the number I have from the total submissions stored in wordpress should be equal to the number of pageviews I find under “Pages” from the section “Behavior” in matomo, but that’s not what happens.
We did the same procedures for 4 different sites and in all of them data don’t match.
For example, on one site I have 4226 submissions stored in wordpress but Matomo claims that the thank you page has been visited only 3982 times (around 6% discrepancy) but in another site we have 3208 pageviews tracked by Matomo (which mysteriously in this case tracked the pageview twice per same visit log in the majority of the logs) versus 1591 submissions from wordpress.

Can someone explain what’s the reason behind it? How can we justify the discrepancy?

Thank you for your clarifications!

No one has a clue? :frowning: