@Joey Marshall, thank you for posting this question on Microsoft Q&A and apologies for the delayed response.
The primary reason for this issue is that the Diagnostic Settings was not enabled to forward MIcrosoft Entra logs to Log Analytics workspace, as mentioned in the prerequisite - Send Microsoft Entra sign-in logs to Azure Monitor.
I would suggest following the steps and ensuring that the diagnostic logs are enabled.
In case this was already followed, and you are still not able to see any logs flowing into the LA workspace, I would request opening a support case with Azure, so that the backend logs can be reviewed to understand the reason for this issue.
Hope this helps.