Steps to reproduce:

1. Create Proxy Group of 2 proxies - prx1 and prx2;
2. Start monitoring one Agent or Agent 2 with a proxy Group and ServerActive set to prx1;prx2
3. Stop Zabbix Server or break network connection
4. Restart Agent/Agent2 or just wait, get:

5607:20260519:160555.001 cannot send list of active checks to "1.2.3.4": host "agent_test_host" redirected address is being reset

Expected:
If server is not available  - continue monitoring with an existing configuration.