Hello @Josh Madakor ,
Thanks for reaching out to the Q and A platform.
Please make sure that you are running the Query on the right Log Analytics workspace, that has been attached in the NSG flow log.
Here is the observation on the lab I have created.
Flow Log been created:
Which has been attached to the workspace as mentioned below, and its Version 2 flow log:
Now running the query on the workspace:
I have a workspace, where it is not attached to the NSG flow log, there I could see that AzureNetworkAnalytics_CL not been recognized.