That will the default behaviour across all clouds. Services will be places on different hardware during restart, maintenance or other unexpected failures.
You can try with Azure dedicated hosts where a physical server is allotted to you. This MAY solve your problem. But in that also you need to place vms and then use them. Physical server assigned also can change but not as frequently as reboot. Please check if your service is suitable for this and then use. Other than this service, no other service will maintain the same hardware.