After upgrading our 2.4.7 environment to 3.0.2 two proxies are not receiving correct data from the server, therefor no data received from those proxies.

Error messages in the log (zabbix-proxy):
Message from 10.243.130.12 is shorter than expected 1859411 bytes. Message ignored.
End of get_data_from_server():FAIL
cannot obtain configuration data from server at "10.243.130.12":

From the server logs
sending configuration data to proxy "CZ_Zabbix_proxy_01" at "172.22.2.251", datalen 1859411
cannot send configuration data to proxy "CZ_Zabbix_proxy_01" at "172.22.2.251": ZBX_TCP_WRITE() timed out

Heartbeat messages are OK, from the GUI the "last seen" value is a few seconds.

There are other proxies on the local network and some remote ones via ipsec vpn which are working properly.

Before the upgrade everything was fine.