The partial network outage has been resolved. We are awaiting updates from our network supplier on the cause of the issue.
Update: An RFO has been published by our network supplier and can be read at https://www.bit.nl/uploads/images/PDF-Files/RFO-20210217-172816.pdf
Our monitoring detected some interruptions on parts of our core network. Engineers are currently investigating the issue. Customers may experience degraded performance on some services until the issue has been resolved.