An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
Hi Natasha Ofman,
Welcome to Microsoft Community.
From your description, your Internet connection disconnected after about 30 minutes you turn on Defender.
Did the network become connected after that automatically?
Did the VPN turn on as soon as you turned on Defender?
If there's any incorrect in my reply, please feel free to point out.
Thank you for your understanding.
Best Regards,
Thomas.L - MSFT | Microsoft Community Support Specialist