How to use Vagrant and Docker-for-Windows on a Hyper-V system?
Confirmed by this answer on SO referencing  Microsoft technet once Hyper-V is activated it mask the VT-X instructions of the processor to the OS on top of it and windows run like a guest.

Docker for Windows need hyper-V to work, so disabling it is not really an option.

There's no way to have virtual box running on top of Hyper-V and that's quite normal, you should not run an hypervisor within an hypervisor, they'll fight to orchestrate hardware acces.

The best workaround in my opinion is to create hyper-V virtual machine from vagrant with the hyper-V provider instead of virtual box machines, this way you can create VM or container on the same session.

Side note, vagrant already have a note about this in the hyper-v provider documentation page (found while searching the link to add above):


  Warning: Enabling Hyper-V will cause VirtualBox, VMware, and any other virtualization technology to no longer work. See this blog post for an easy way to create a boot entry to boot Windows without Hyper-V enabled, if there will be times you will need other hypervisors.