I also had one or two �Openreach system errors� during my install which are just internal Openreach ordering bugs/glitches. They got resolved fairly quickly and it was nothing majorly concerned to be about. I can understand your frustration but i would remain optimistic that you�re very close to going live 
Not as close as me though.
Engineer called this morning to say with us 9-ish, to fit modem. I let him know the ONT was already installed and on the wall. Arrived, made him a cup of tea whilst he spent 5 minutes to test the fibre signal. All good, commissioned ONT, and we then sat for circa 10-minutes waiting for connection to complete. A solid green light. Added details from Cerberus to router and plugged in.
First speed test - 15 Mbps ?? - Checked router settings and turned off smart queues set at 20Mbps limit
Second speed test - 150 Mbps better - Checked router settings and turned off IPS (that's about a USG-Pro-4s limit)
Third speed test - 288 Mbps - Bingo! Bear in mind I had made no attempt to turn off guest wifi, or disable any of the other network equipment on site (some 80+ devices)
Roughly 10-months from first contact with the Cerberus to deployment. I have not been able to fault communication throughout the 10-months process. Vruti has been awesome.
A big thanks to the team at Cerberus and today I will be mostly streaming or running speed tests!
I must say one of the big differences I noticed was an absolutely rock solid 15ms ping (google averages 12ms-15ms). Previously on our wrecked copper we would get 40-50ms but regularly in excess of 150ms. 15ms is awesome for rural North Yorkshire.
Edit: tidied up some other settings and stopped a couple of radio streams and re-ran test. Not bad for a 300/30 service.
https://i.imgur.com/tcbR4VL.png
Edited by F00tS0re (Tue 12-Mar-19 15:08:12)