The Netqos ReporterAnalyzer Watchdog service is using the "free" column from the output of the "top" or "free" commands to calculate the memory utilization.
For example below you see only 213M for the free column, but 4.6G showing as available.
As a workaround if you can't upgrade to NFA 22.2.7 yet, you can follow the steps below to disable memory utilization warnings in the System Status page.
1. Go to the Admin->Watchdog Settings page in NFA.
2. Chang the Memory Utilization field from the default value of 80 to 100.
3. Click "Save".
4. Go back to the Admin->System Status page and the memory error should clear.