Steps to reproduce:

1. Create a host with SNMP interface with IP of 192.0.2.77 and an snmptrap.fallback item
2. Add three trap entries to the trap file

   printf '10:00:01 2026/06/24 ZBXTRAP 192.0.2.77\nVARBINDS:\n  .1.3.6.1.4.1.2011.2.251.20.1.3.10.0 type=4 value=STRING: "trap-1"\n\n' >> /var/lib/zabbix/snmptraps/snmptraps.log
   printf '10:00:02 2026/06/24 ZBXTRAP 192.0.2.77\nVARBINDS:\n  .1.3.6.1.4.1.2011.2.251.20.1.3.10.0 type=4 value=STRING: "trap-2-\0-nul"\n\n' >> /var/lib/zabbix/snmptraps/snmptraps.log
   printf '10:00:03 2026/06/24 ZBXTRAP 192.0.2.77\nVARBINDS:\n  .1.3.6.1.4.1.2011.2.251.20.1.3.10.0 type=4 value=STRING: "trap-3"\n\n' >> /var/lib/zabbix/snmptraps/snmptraps.log
   

Result:
trap 1: stored
trap 2: truncated at the NUL byte
trap 3: lost - absent from Latest Data, no log entry at any debug level

Expected:
All three traps stored as values of snmptrap.fallback