WhatsApp Message Delivery Discrepancy on OPNsense Firewall After Recent Unbound

[Millz]

Greetings forum members, I recently installed the OPNsense firewall, and last week, a colleague made adjustments to the Unbound DNS settings, specifically altering the "Type of DNSBL" and adding a new list. Since then, an issue has arisen where Android users seamlessly receive WhatsApp messages, while iPhone users experience disruptions unless connected to an alternative network. Seeking insights and solutions to address this discrepancy in WhatsApp message delivery on the OPNsense firewall. Appreciate any assistance.