in zabbix 4.4, LLD JSON not convert macro to empty if is send null. In other version its is OK

I think that change in ZBX-9146 caused the behavior. This behavior is expected or is a bug?

example if I send null to {#PDB}

{
 "data":[
 {
 "{#TST}":"example",
 "{#PDB}":null
 }
 ]
}