Symptoms:
VMware NSX for vSphere 6.4.x
This issue occurs when the NSX Edge is created from vCloud Director and modified in NSX Manager. When the NSX Edge was created as "Compact" from vCloud Director, it only provided the NSX Edge with 256MB memory.
When the NSX Edge was upgraded from the NSX side, the setting still remained.
During troubleshooting, a check was done on the the .vmx file on the NSX Edge and found this entry:
sched.mem.max = "256"
This would mean even though the edge had 8 GB memory configured, edge would only get 256MB.