All providers? All hardware?
There will be some with the white openreach modems and secondary router, and some with HH5, BrightBox2 or latest SkyHub
Some routers do seem to take a while to get their act together, i.e. 5 to 10 minutes from when first connected, which seems forever when waiting for them, and I even after two months if I restart everything I get the odd timeout doing the PPPoE stuff.
If it is everyone and all providers and is JUST one cabinet affected, then wiring in cabinet has been done wrong, or a failure in the actual VDSL2 DSLAM