This issue tracker is for bugreports. Please see https://zabbix.org/wiki/Getting_help for support options.
Alternatively, if you have commercial support, you might want to move this issue to your dedicated project.
On top of that, more recent agent version is not officially supported by older server/proxy - see https://www.zabbix.com/documentation/3.4/manual/appendix/compatibility and https://www.zabbix.com/documentation/4.0/manual/appendix/compatibility .
Please be advised that this section of the tracker is for bug reports only. The case you have submitted can not be qualified as one, so please reach out to [email protected]
for commercial support or consultancy services. Alternatively, you can also use our IRC channel or community forum (https://www.zabbix.com/forum) for assistance. With that said, we are closing this ticket. Thank you for understanding.