We are observing issues in delivering callbacks properly to shops properly. We have identified that simply.com has been victim for a DDOS attack.
Read and follow this status directly on Simplys website: https://www.simply.com/en/serverstatus/
We are following the situation closely.
The initial status from 04.00 CEST:
"Our DNS servers are currently the target of a massive DDOS attack. This can cause problems with DNS lookups, which in turn may affect email and web sites for domains using Simply.com's name servers. We are working on mitigations. Our nameservers are currently not responding, because our Internet provider is doing mitigation. We are working with them to fix this."