Hello!
You cannot change the Type of the NIC in the GUI. Here you can only delete it and add a new one with the correct type but this will also genereate a new MAC Adresse for your VM. For changing the NIC Type and preserve the MAC Address i always use PowerCLI/PowerShell -> PowerShell Gallery | VMware.PowerCLI 12.0.0.15947286
Open PowerShell and install the PowerCLI Modules:
Install-Module -Name VMware.PowerCLI
Now you can connect to your vCenter with:
Connect-VIServer -Server yourvcenter.fqdn
And change the NIC Type of your VM (the VM must be PoweredOff) - in your case:
Get-VM -Name SDWAN_vESXi | Get-NetworkAdapter | Set-NetworkAdapter -Type Vmxnet3
Hope this helps a little bit