i think you can tryopnsense-patch 387fc59and disable it via guior place aggressive-nsec no somewhere in /usr/local/opnsense/service/templates/OPNsense/Unbound/core/advanced.confand Apply unbound settings
2024-09-18T13:46:40 Error unbound [54445:2] error: SERVFAIL <somedomain.tld. A IN>: all servers for this domain failed, at zone somedomain.tld. upstream server timeout 2024-09-18T13:43:36 Error unbound [17415:1] error: SERVFAIL <xx.xx.xx.xx.in-addr.arpa. PTR IN>: all servers for this domain failed, at zone 64.92.188.in-addr.arpa. no server to query no addresses for nameservers 2024-09-18T13:43:36 Error unbound [17415:0] error: SERVFAIL <xx.xx.xx.xx.in-addr.arpa. PTR IN>: exceeded the maximum nameserver nxdomains 2024-09-18T13:43:30 Error unbound [17415:3] error: SERVFAIL <xx.xx.xx.xx.in-addr.arpa. PTR IN>: exceeded the maximum nameserver nxdomains 2024-09-18T13:33:04 Error unbound [17415:3] error: SERVFAIL <85.21.107.40.zen.spamhaus.org. A IN>: exceeded the maximum nameserver nxdomains 2024-09-18T13:32:26 Error unbound [17415:2] error: SERVFAIL <somedomain.tld. A IN>: all servers for this domain failed, at zone somedomain.tld. from 194.0.34.53 no server to query nameserver addresses not usable