In some cases, when NitroPack is enabled, the pixels from the PixelYourSite plugin won’t fire.
There’s an easy fix.
All you need to do is:
Navigate to the PixelYourSite settings in the wp-admin
Add the NitroPack user agent Nitro-Optimizer-Agent to the “Exclude these robots from blocking” setting
Save your settings
After saving your settings, everything should work as expected, and the pixels should be fired.