az create vm --vnet-name creates vnet of existing vnet name

Finally found this detail via a web search, after many confusing hours, where it creates second vnet in the same subscription of the same name.
To description of--vnet-name ( az create vm ), add something like "To use an existing VNET in a different resource group, specify the only full subnet ID."

---
#### Document Details

⚠ *Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.*

* ID: 152b549b-d4b3-13e5-081c-c604b6e4d89e
* Version Independent ID: 3f79be78-ce75-ad31-304b-bad7d475ec9e
* Content: [az vm](https://learn.microsoft.com/en-us/cli/azure/vm?view=azure-cli-latest)
* Content Source: [latest/docs-ref-autogen/vm.yml](https://github.com/MicrosoftDocs/azure-docs-cli/blob/main/latest/docs-ref-autogen/vm.yml)
* Service: **virtual-machines**
* GitHub Login: @rloutlaw
* Microsoft Alias: **routlaw**