Есть обходной вариант, можно подключиться к БД заббикса и в таблице items выполнить update:
zabbix=# select name, delay, history, timeout from items where name like '%access%' limit 30;
name | delay | history | timeout
---------------------+-------+---------+---------
access.log(5xx) | 30s | 90d | 3s
access.log(2xx|3xx) | 30s | 90d | 3s
access.log | 30s | 90d | 3s
access.log(4xx) | 30s | 90d | 3s
access.log(3xx) | 30s | 90d | 3s
zabbix=# update items set delay = '60s' where name like '%access%';
UPDATE 5