Disable 802.1Q from a virtual network (using ovswitch driver)

I defined a public virtual network with this template:
BRIDGE = “br-ex”
BRIDGE_TYPE = “openvswitch”
DESCRIPTION = “Network with public IPs”
DNS = “..200.250”
GATEWAY = “..158.1”
VN_MAD = “ovswitch”

But when I check my ovswitch bridge a 802.1Q tag is associated to the VMs interfaces:
ovs-vsctl show
Bridge br-ex
Port enp216s0f1
Interface enp216s0f1
Port br-ex
Interface br-ex
type: internal
Port one-21-0
tag: 3
Interface one-21-0

I can’t connect to this VM from the same KVM node or from external nodes. If I remove the tag:
ovs-vsctl remove port one-21-0 tag 3
Then I can connect to this VM.

Is there any way to remove the VLAN tagging from an Openebula’s virtual network which is using ovswitch bridges ?