Steps to reproduce:

1. Zabbix server 7.0.28 with two or more active proxies 7.0.28 in a proxy group.
2. Host monitored by the proxy group, with an active-agent log item using skip mode.
3. Trigger: length(last(item))>0 and nodata(item,20m)=0.
4. Produce one matching log line so the problem opens; then stop producing matching lines entirely.
5. Observe that the problem does not close after 20 minutes and remains open indefinitely, while proxies stay online.
6. Replace nodata(item,20m) with nodata(item,20m,"strict") — the problem now closes 20 minutes after the last value.

Result:
nodata() is not processed correctly correctly. 

Expected:
nodata() processed correctly.