Can Ping Non-Existent Subdomain

I can ping [anything.mydomain.com](https://anything.mydomain.com) and get a response back from a few of our laptops. I am trying to figure out why this is happening. They all use Cisco Umbrella for DNS resolution. If I ping that from onsite, it comes back as ping cannot find the host. If I do it from a personal computer it comes back the same. From like 200+ devices, it also comes back as cannot find the host. But from like 2-3 laptops, I get a ping reply. Nothing is in the host file, I have tried flushing the DNS, cant seem to figure out how this is resolving. Our internal and external domain matches, not by my choice. But I have no anything record on our internal DNS, nor do I have a record for it out at our external DNS. https://imgur.com/OXW2uhL