And don't forget about default macro limit

But macro seems ok: {$LOAD_AVG_PER_CPU.MAX.WARN} 1.5

Could you please be so kind and provide whole trigger expression, thanks !

Template: Template Module Linux CPU by Zabbix agent
Item name: Load average (1m avg)
Item key: system.cpu.load[all,avg1] (and 5, 15)
Trigger description: Load average is too high (per CPU load over {$LOAD_AVG_PER_CPU.MAX.WARN} for 5m)
Trigger expression:

{Template Module Linux CPU by Zabbix agent:system.cpu.load[all,avg1].min(5m)}/{Template Module Linux CPU by Zabbix agent:system.cpu.num.last()}>$LOAD_AVG_PER_CPU.MAX.WARN} and
{Template Module Linux CPU by Zabbix agent:system.cpu.load[all,avg5].last()}>0 and
{Template Module Linux CPU by Zabbix agent:system.cpu.load[all,avg15].last()}>0}  

My bad, sorry, didn't see division by system.cpu.num

That's OK, thank you for your report, closing as Won't fix, it could be good to change from "all" to "percpu" and remove division but then it would not work on Zabbix agents prior to 2.0 if such would be used.