Thank you for sharing the link!
First, pay attention to the errors in the console. Here is what I could see on the first page

and the following error is on the contact us page (second page):

Regarding the tags that may fail to fire, I have looked at the setup with the Launch Inspector and did not find the rule "PL : Top : All Pages". However, there is a rule "PL : Top : All : All Pages" with some custom code that should fire gtag.
The 6th action in the rule looks as follows, is it the tag you were referring to as the failed tag?
if (_satellite.getVar("are Targeting Cookies Allowed")) {
var currentTagName = "Performics Google Global Site Tag";
_satellite.setVar("Current Tag Name", currentTagName);
_satellite.getVar("Tag Started");
_satellite.getVar("ctl.util.loadScript");
//Global site tag (gtag.js)
_satellite.ctl.util.loadScript({
src: "//www.googletagmanager.com/gtag/js?id=DC-10006467",
preLoad: function () {
window.dataLayer = window.dataLayer || [];
window.gtag = function (){dataLayer.push(arguments);}
gtag("js", new Date());
gtag('config', 'DC-10006467');
gtag("config", "DC-9129572"); // PFX Global Site Tag
gtag('config', 'AW-626667738'); // added 8/7/20
gtag('config', 'AW-608245086'); // added 8/31/20
}
});
_satellite.setVar("Current Tag Name", currentTagName);
_satellite.getVar("Tag Finished");
}
The call of "_satellite.ctl.util.loadScript()" looks quite odd. Do you know what this is and why this is used?
A similar call is also used in the 8th action too.