This is a message from our CDN provider:
Hello, the issue appears to be inside some parts of the AS5432 (Belgacom-Skynet) ISP network in Belgium. All of the probes that we used for testing inside their network (53) were able to reach our anycast DNS successfully, but some of them fail during name resolution. It is always the same probes failing, so it does not appear to be random. The issue is likely related to a resolver inside their network, and we will attempt to contact them to notify them.