Steps to reproduce:

1. Temporary spike in % value cache used >75%
2. zabbix[vcache,cache,mode] item switches to 1 = "low memory mode"
3. Temporary spike drops below 75%
4. zabbix[vcache,cache,mode] item stays at 1 = "low memory mode"
5. Only zabbix serevr daemon restart clears trigger

Result:

Temporary spike:

zabbix[vcache,cache,mode]

Expected:
Item switches back to 0 after value cache % drops below 75%