Thanks for the update. It certainly is unusual as we don't tend to see this type of issue here with Hyperoptic. When it works, it's usually pretty good.
Hopefully Hyperoptic have been able to do the usual things like try a new port on their local switch, swap any cabling where possible, etc. Was the engineer able to replicate the fault with their own equipment, so they can be sure it's an issue on their side?
Views expressed are mine and not necessarily those of my employer.