Steps to reproduce:

1. Direct Upgrade Server from 4.4 to 5.2
2. Install Zabbix-Agent2 for migration from zabbix-agent (4.4)
3. Disable and/or removal of original agent
4. Restart agent2 - never loads proper conf file (even after updating). Constantly reads package installed variables when tail log (i.e. host: Zabbix server, 127.0.0.0:10051, etc)

Result:
Server 4.4 upgrade to 5.2 server packages, fresh install of agent2 - agent 2 never loads correctly after edit of .conf file, retains default package variables on restart
Expected:
Agent2 starts normally after edit to environment variables in .conf file

Workaround:

Upgrade to 5.0 first, install Agent2, disable/remove original agent. Edit .conf file and restart - Agent2 loads normally with proper .conf configured variables.

Then upgrade to 5.2 after all zabbix service upgrade, runs normally when tail on Agent2 log (i.e. proper host name and server is not package defaults).