ZBX_NOTSUPPORTED: 'Unable to connect: permission denied' to '127.0.0.1'

[Spectator]

I installed zabbix 6 on a raspberry instead of the previous 5.4. Raspbian 10 was replaced by raspbian 11, so a complete reinstall was performed. Based on this, I performed the installation, but the agent is zabbix-agent2:

https://bestmonitoringtools.com/how-to-install-zabbix-on-raspberry-pi-raspbian/

The raspberry has an RS-485 panel that reads a device using the modbus protocol.
This command perfectly returned a value under the previous version of Zabbix:

zabbix_get -s 127.0.0.1 -k modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]

But now it returns:

ZBX_NOTSUPPORTED: Unable to connect: permission denied

In zabbix-agent2.log I see this:

2022/02/17 19:16:37.358960 received passive check request: 'modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]' from '127.0.0.1'
2022/02/17 19:16:37.359555 [1] processing update request (1 requests)
2022/02/17 19:16:37.359833 [1] adding new request for key: 'modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]'
2022/02/17 19:16:37.360034 [1] created direct exporter task for plugin 'Modbus' itemid:0 key 'modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]'
2022/02/17 19:16:37.360479 executing direct exporter task for key 'modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]'
2022/02/17 19:16:37.360846 failed to execute direct exporter task for key 'modbus.get[rtu://ttySC0:9600:8e1,1,3,20480,,float]' error: 'Unable to connect: permission denied'
2022/02/17 19:16:37.361121 sending passive check response: ZBX_NOTSUPPORTED: 'Unable to connect: permission denied' to '127.0.0.1'

In the agent2.conf, Server=127.0.0.1 and ServerActive=127.0.0.1

I'm just unable to figure out where the problem might be
Do you have any ideas where the problem is?

[Spectator]

Okay, I found a solution to the problem at the end of this topic:

https://www.zabbix.com/forum/zabbix-help/421880-modbus-zabbix-proxy