Windows Server 2019 memory utilisation

Question

The memory usage goes up to more than 98% without using significant resources on the Server. When the Server is restarted, the memory usage is normal as indicated in screenshot 1. But after a while without using any resources, the memory usage goes up to 84%. How can we overcome this problem? How can we reduce the memory utilization when the machine is not utilized fully?

Answer 1

What roles or applications are installed? What consumes the MEM?

Answer 2

RSAT tools are installed on this server and here is the snapshot

Answer 3

Might also try from a clean boot.
https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd