Fix Intermittent DNS Failures on Windows Server 2012 R2

I'm facing intermittent DNS failures on my Windows 2012 R2 host and four 2012 R2 Hyper-V servers. These issues are causing my servers and host to lose network connectivity and their connections to each other.

My setup includes:
- A VPN Router: TP-Link AX3000 (192.168.16.1)
- A Dell r720 running Windows Server 2012 R2, named HOST2
- Four Hyper-V servers with the following names and IPs:
- MCOV-ACCT01 (192.168.16.20)
- MCOV-MRCH01 (192.168.16.17)
- MCOV-DC01 (192.168.16.15)
- MCOV-DC02 (192.168.16.16)

Recently, I made some changes to my network settings, which may have contributed to these issues. However, I don't have any specific error messages or logs that could help diagnose the problem.

The ideal freelancer for this project should have:
- Extensive experience with Windows Server 2012 R2 and Hyper-V
- Strong troubleshooting skills for DNS issues
- Knowledge in network configuration and settings
- Ability to work without specific error messages or logs.

I need these DNS issues fixed as soon as possible so that my servers can maintain stable network connections.