Robot vacuum won’t connect to WiFi

I recently bought a Roomba j6 robot vacuum, but have been unsuccessful in connecting it to the WiFi (I’ve extensively troubleshoot this issue). The iRobot app says I’ve successfully set up the device, but the immediately unable to use it because it says it’s not connected to the network. The Roomba is 5 GHz compatible and uses WPA 2 network encryption (the same I use on the xfinity Gateway XB6 I use. The Xfinity app says that this device is connected and when I run the troubleshooter tool for the Roomba, it says that there are no issues.

I previously owned a Roborock vacuum which also had WiFi connection issues where it could only briefly connect to the WiFi. This is why I’m convinced this is a Xfinity Gateway issue.

** due to a website bug, I’ve had to type this out three times! Very frustrating. The tag section DOES NOT WORK**