Help: Third Party ADS code not work

The problem: we are trying to insert the a code to implement a third-party advertisement system based on Google Tag. This code is to coexist with current Ad Sense ads.

We have tried from multiple places to have it “live” on our webiste, unsuccessfully.

Places we tried:
– the slot included in the template
– template’s header.php directly from theme’s root
– template’s header.php directly from a Newspaper child folder.

Here are our conclusions:

You can post content within the header.php, and we can see it live in production environment, i.e. general comments or random text. However, the previously mention code does not update.

Here the steps we did.

1st. We enter the theme folder by FTP and then create a child.
2nd. We create a header.php with the modifications we needed.
3rd. we purged in wordpress
4th. we review the changes.
nothing happened.
We did this process repeatedly and the changes we made to “header.php” were not reflected.

then:
we made a backup of “header.php”
We put the changes in a dummy copy of the “header.php”.
We purge
The changes did not take effect.

then:
We eliminated the “header.php” that we were working on, to see if the changes actually took effect. We purged. On the page, the header disappeared. We retrieve the original “header.php”. Then purged. The page header appeared again.

These steps are carried out repeatedly.

In addition, we tried to create a log in the console and we could not see it either, meaning there was no error logging for none of the above steps.

Hellooooo?