Previously, we encountered a similar issue even with version 9.2 as per the requirement.
There is a known bug: https://kb.sitecore.net/articles/828414 for 9.0.1. Not exactly sure if it's working for 9.0.2.
For more detailed troubleshooting, I recommend referring to the following resource: https://bala.one/sitecore-device-detection/. This post contains information on how to verify the functionality of device detection.
If you still want to utilize Sitecore Device Detection and there are no error messages in the Sitecore logs, I suggest raising a support ticket to the Sitecore team for further assistance.
They will be able to provide you with more specific guidance or hotfix.