Solarwinds reports 80-90% memory usage for the Solarwinds server. Windows Server 2016 says less than 21% usage (the VM has 24GB RAM).

We've (network engineers) have been bugging the systems guys to up the memory on our VM instance that powers our Solarwinds server.  We've been bugging them because the Memory Capacity Forecast Chart keeps throwing alerts that our memory usage is over 90%.  They finally agreed to add in another 8 GB, bringing us up to 24 GB.  This only resulted in a 7% drop within the chart.  The systems guys then sent us a screen shot of the Windows server memory usage and it shows only 5 GB is actively being used.

Where is this discrepancy coming from and how can we resolve it?