Full red BQM with WAN ping enabled (5G router on 3)

Hi forum
I have a 5G router from 3 (5G CPE Pro) and everything was going well. I had DDNS configured on the router using no-ip.com (since the IP kept changing, and I need a static domain for work to whitelist me!) with a BQM set up to point at that domain name. However, at some point (possibly a router update) BQM stopped working, and shows 100% packet loss all the time now (whether pointing at the domain name or the WAN ip).

Yes, I have enabled WAN port ping in the Firewall settings.

I have tried several things, including disabling the router firewall (temporarily) to no avail. One curiosity that did appear during my testing was a pathping from my PC (which is wired to the router) to 8.8.8.8 (google) gets stopped after leaving my router:

Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:
0 ************** [192.168.8.200] <- this is my PC
1 hirouter.net [192.168.8.1] <- this is the router admin page
2 * * * <- this shows a timeout on the ping

Similarly, a tracert shows the step after the router as timing out (but it then continues beyond).
Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms hirouter.net [192.168.8.1]
2 * * * Request timed out.
3 9 ms 9 ms 9 ms 172.**.**.**
etc

Could this have anything to do with BQM not being able to access my router?

Running https://www.thinkbroadband.com/tools/traceroute fails to get to my router, this is the total output:
1 thinkbroadband-gw2.core-rs2.thdo.ncuk.net 15 15 0ms 0ms 1ms
2 po4-31.bdr-rt3.thdo.ncuk.net 15 15 0ms 0ms 0ms
3 xe-0-0-10-0.a01.londen12.uk.bb.gin.ntt.net 15 15 0ms 1ms 1ms
4 ae-3.r20.londen12.uk.bb.gin.ntt.net 15 15 0ms 1ms 10ms
5 ae-1.r04.londen05.uk.bb.gin.ntt.net 15 15 1ms 1ms 1ms
6 ae15.cr11-lon2.ip4.gtt.net 15 15 0ms 6ms 22ms

Running https://www.ipaddressguide.com/ping has 100% packet loss to my WAN ip or DDNS hostname.

I hope you have some ideas? I feel like it's a lost cause, and that my ISP is blocking pings before they get to my router... Happy to provide more info, or perform other tests, as required.

Thanks in advance
Malcolm

Update to the situation, for future readers:
I restarted my router this morning (for the Nth time!), after I think it auto-restarted last night and put my Google Nest Hub out of action (everything else worked fine). And now I have a working BQM! I have taken note of all the Device Info on my router, in this working state, in case it breaks again, and I can then do a comparison. It is to be hoped though, that the issue was a firmware problem, and it has been resolved.
For reference, pathping and tracert from my PC show the same output as below. But the traceroute tool and the online ping utility are both now able to complete successfully.
It is a mystery, I just hope it remains solved!
Malcolm

Daily auto restart (at something like 3am) was a default in the Huawei 5G box I had from Voda. Sometimes it would need a full power/on off as it stuck itself into a 4G only loop forgetting that 5G was there. I’m not sure whether it was VF stabilising work on our nearby masts at the time (central London) but it got more stable towards the middle-end of the contract in this respect at least. Water under the bridge now somewhat I suspect as we were quite early on in the 5G enablement of the local masts (2019 Highbury /Canonbury).