A very minor spacing consistency issue in https://www.zabbix.com/documentation/4.0/manual/appendix/items/sensor .

sensor[k8temp-pci-00c3,temp, max] or sensor[0000:00:18.3,temp1]

sensor[smsc47b397-isa-0880,in, avg] or sensor[smsc47b397.2176,in1]

Notice how in the first example on each line there's space after the second comma - in all other examples and locations there's no space.