How to reproduce:

• create discovery rule with key "discovery" with type "Zabbix trapper"
• create item prototype with name "{#I}" and key "item[{#I}]"
• send discovery data zabbix_sender -z localhost -s host -k discovery -o '{"data":[{"{#I}":""}]}'
• see screenshot
  

Same problems with trigger names, tags, graph names, host names...