If you try to use nvm under Windows and load default version of node like (expected) :
you will see :
A version argument is required but missing.
Reason seems to be that : .nvmrc is not supported (under Windows). More on this here : https://github.com/coreybutler/nvm-windows/issues/388#issuecomment-418513601
But what you still can do under PowerShell is :
nvm use $(Get-Content .nvmrc)
and you are good to go.
Hope you saved some time.