Multiple contacts being created for a single visitor

Are you able to reproduce the issue? Contacts are tracked based on the cookie - isn't it possible that there is some cookie customization? What is the default cookie level? Do the visitors have to agree with the tracking, is there any consent agreement? Then I would also check the environment - load balancers and other tools used which could modify the requests.
What changes were done? Not only in Kentico but also in the environment.

The issue happens consistently, every day, all day. As I dig through the .NET core code I'm not seeing any customizations to the "CurrentContact" cookie or changing the site cookie settings. The System > Cookie setting is currently set to All. We add and modify a few other custom cookies, but no system cookies.

We do have a cookie consent setup exactly how it's described in the docs. As far as I'm aware, the Azure Web app settings are as any other site we've set up. It does have Azure Front Door in front of it as we're blocking specific countries' access. There is only one web server (no web farm setup).

The site does have a lot of Google Tag Manager tags and triggers that load with it. We've went through some extensive investigation and found them to be less of an issue than initially determined.

When we hook Application Insights up to the web app, we're seeing a POST to /Kentico.Activities/KenticoActivityLogger/Log generates over 8000+ different operations. Many appear to be recursive in nature.

Just at a loss of where to dig into further and find possible solutions.

If this is happening for this one project only, there must be some difference. If possible, I would test it locally - to see whether it creates contacts. If yes, then the issue will be in the project - in admin or in the front end code. If not, there will be something in the environment. I have checked the history. Really loooong time back and in the past there was one similar issue where they were using some load balancer setup which somehow modified the requests which interfered with the contact cookie creation - so each request looked like new visitor to Kentico.
Is the contact cookie created in your browser when testing?

Hi Brenden! This sounds like a real headache. Since you're using Azure Front Door, check if the client IP is forwarded correctly. If Kentico can't map sessions via headers, it'll just keep spawning new GUIDs. Also, look at the 'SameSite' cookie policy—it often clashes with Front Door. Hope you get it sorted!