Dissapearing Pixel

I have added my re-targeting pixel in the custom field, when I view page source the pixel is there, however I noticed no audience is created even though there has been traffic to my page, when I check the page source again, is not showing anymore. I have to go back to wordpress and update the page in order for it to show again.
I do have another pixel on a separate page, and that one is working properly.

Not working: http://biochromato.com/smart-evaporator/
working: http://biochromato.com/slit-seal

thank you

https://wordpress.org/plugins/acf-retargeting-addon/