The script is working for the single page website and not on the main website

Hi @dejan , our booking system has one script where the user can open the booking flow as a popup, for the single page website is working normally but for the main website, sometimes it works and sometimes not, it opens on other tabs.

Is there anything I need to do to force the script to work?

Here is the single page one:

And the main one:

I tried to add to Head End, Head Start… same results, and it happens the same with the embed code section.