Struggling to get BQM working after changing router

Hello

I changed my router recently from Asus to Synology and I'm struggling to get BQM working again.

Because I have BT FTTP and I want to keep Digital Voice working, I have to keep my BT SmartHub router connected to the ONT.
As this router can't be set in modem only mode, I deactivated most features on it (DHCP, firewall, etc...), put a static IP as WAN address in my Synology router, and put this IP in the DMZ of the BT Hub (so double nat, but that works for everything else).
I then registered a DDNS with Synology, and created a rule in the firewall to allow ICMP traffic from the WAN interface.

I checked that I could indeed ping the DDNS host from outside, it's all good.
Now, this was working perfectly with this same setup and my old Asus router, but the graph is desperately all red with Synology setup, and I don't understand what I missed, as the ping is working from other outside computers.

Here is a link to my monitor:
https://www.thinkbroadband.com/broadband/monitoring/...

If someone has an idea of what I've done wrong here, I would be grateful.

You have to allow your device to respond to pings (ICMP) from TBB address. It is in the setup guide

But this is already the case. As I said, I'm able to ping my device from outside the network already, so I don't understand why the monitor can't do it

I wonder what is responding to pings then?
The guide does specifically states that that BT router is not supported though.

Not Supported*
BT Home Hub or Smart Hub
PlusNet Hub Zero / Hub One (aka BT Home Hub 5a)

BTW - Who are you using for DDNS as this has caused me issues recently.
My TwoDNS became very intermittent so I swapped to my alternative option.

Edited by smouty (Fri 23-Sep-22 12:24:00)

In reply to a post by smouty:

I wonder what is responding to pings then?
The guide does specifically states that that BT router is not supported though.

Not Supported*
BT Home Hub or Smart Hub
PlusNet Hub Zero / Hub One (aka BT Home Hub 5a)

It's supported with the configuration the OP has used.

None of the (residential/consumer) BT Hubs can respond directly to pings n their own but they will forward the pings to whatever device is placed in the DMZ.

Placing the Synology router (or any router) in to a DMZ on the BT Hub works perfectly with a BQM.

I do manage to have the ping working as I mentioned.
What I don't understand is, if I can ping, why can't BQM ?

Maybe something is timing out. Have you pinged from various website ping tools to check it works across the internet?

yes, I tried various tools, I tried from my phone when on 4G network, it's always working.
I'm away from home at the moment, and I just tried from a network at my current location, works as well.

In reply to a post by Grouzy:

yes, I tried various tools, I tried from my phone when on 4G network, it's always working. I'm away from home at the moment, and I just tried from a network at my current location, works as well.

Odd then, perhaps one to post in Talk To The Staff ?

Can you successfully setup a monitor for it using UptimeRobot?