@fxazure4SBF Thank you for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
This is by design, all the platform metrics are collected and stored by Azure monitor. Azure Monitor stores the platform metrics for 93 days only and you can query the data for past 30 days only as mentioned in this documentation here.
If you want to store the platform metrics for long periods, then you can send metrics to log analytics workspace wherein you can store and retain the data up to 12 years based on the tiers.
Azure Monitor Logs retains data in two states:
- Interactive retention: Lets you retain Analytics logs for interactive queries of up to 2 years.
- Archive: Lets you keep older, less used data in your workspace at a reduced cost. You can access data in the archived state by using search jobs and restore. You can keep data in archived state for up to 12 years.
Hope this helps, let me know if you have any further questions on this.