MAC Address field not populating for all devices

When scanning, not all MAC address fields are correctly populated. Some are blank though they show a ping response time. I checked the ARP table manually and they were definitely present.

Scan network
Look for devices with a ping time and no MAC address

Expected MAC Address to populate in field if device responds to ping


Windows Server 2016 Standard build 14393
Java 8.0.282.8 x64 AdoptOpenJDK - installed via standard installer
3.5.2 and 3.7.4 of the 64-bit scanner

**Logs:**
No logs were generated