WakeOnLan packets throught vlan'd bridge extrange behaviour

[jonsito]

Hi all.
I have this scenario in my Proxmox server

Proxmox server 8.3.3
fiber interface ----- linux bridge ------ linux bridge -+------vm guest 1
                         vmbr1             vmbr1.575    |        eth0
                      VLan aware            no IP       |       IP x.y.z.2
                      No IP assigned                    |
                                                        |
                                                        \----- vm guest 2
                                                                   eth0
                                                                IP x.y.z.3
 Host outside proxmox
 vlan 575
 IP x.y.z.4

interfaces file in proxmox server looks like follows:

.....
auto vmbr1
iface vmbr1 inet manual
    bridge-ports enp99s0f1np1
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-1022

auto vmbr1.574
iface vmbr1.574 inet manual

auto vmbr1.575
iface vmbr1.575 inet manual

auto vmbr1.576
iface vmbr1.576 inet manual
.....
...

When I try to wake up external host from vm guest 1, by mean of "etherwake -i eth0 xx:yy:zz:tt:uu:vv -b" comand works... but bridge vmbr1.575 hangs 5 to10 seconds and during these period all guests under that brigde (either vm guest 1 or 2 ) becomes unaccesible

Suprisingly, creating in guest 1 a second interface "eth1" with no IP assigned, and attached directly to bridge vmbr1, when executing etherwake again on eth0 interface, everything works as expected: no hangs, external host wakes up

Issuing same command but to eth1 interface has no effect.

I've found many references on WakeOnLan issues on virtual bridges, but none about vlan'd ones.
Is this behaviour normal?
what's the difference when adding second ( unused, up, but no ip assigned) interface?
what's the right way to do WoL in this scenario, without adding extra interface?
Sorry for my poor english. Also, my knowledge in virtual bridges is no so deep...

Thanks in advance
Juan Antonio Martínez
E.T.S.I.Telecomunicacion - UPM