I am using NextDNS as the system-wide DNS on Android (via Private DNS / NextDNS app). Other apps consistently use NextDNS as expected. However, in Firefox for Android, even after explicitly disabling DNS over HTTPS (Secure DNS), I still observe that some DNS queries appear to be resolved by other DNS providers. This behavior is intermittent and occurs on both Wi-Fi and mobile networks. My understanding is that when DoH is disabled, Firefox should strictly use the system DNS resolver. So my questions are: Does Firefox for Android have any internal DNS fallback or alternative resolution path even when DoH is turned off? Is this behavior expected by design, or could it be a bug? Are there any additional settings or advanced options required to force Firefox to always use the system DNS? Any clarification would be appreciated.