Unknown Device Joined my Wifi

I received a notification that a device joined my network on a Sunday at 12:50 pm. Number for a device name and misc as device type. I googled the hostname and Apple root certificate info came up. Brand, model and OS are all N/A. I paused the device.

This caused our 5 ghz wifi to go out and the app to freeze up. I couldn't get the app to work until I turned off the wifi on my iphone or switched to the 2ghz wifi. But even on the 2GHz, the app would freeze.

I'm assuming this new device has something to do with the 5ghz wifi but I've searched and can't figure it out. I Googled and found user with similiar issues but it was over 5 years ago. Nothing recent.

The Mac address is 02408BC5FC41 and it says its a 2.4GHz wifi connection type.