Zabbix 3.0.2 cannot obtain data from proxy

[MightBeAWizard]

So, once again I have run into problems. This time the problem is that one of my several proxies is not communicating with my server. Proxies are being contacted every 30 minutes or so and during those time windows it gives me two types of errors:
1) cannot send data to proxy "proxynamehere": ZBX_TCP_WRITE() timed out
2) cannot obtain data from proxy "proxynamehere": ZBX_TCP_READ() timed out

What I have done so far:
- Checked SELinux, it is identical to other proxies
- Connection works on other parts as it should
- I can telnet to that said proxy
- Proxy reports once after I reboot zabbix-proxy
- Latency ain't so high, timeout modified to 30 (not really needed that high)

Any thoughts?

[MightBeAWizard]

There seems to be nothing wrong in anything, except maybe vpn tunnel is somehow not in active state. So I made workaround that "activates" that tunnel and data seems to be moving now.

What I did was I used crontab to start pinging my zabbix server for about 10 minutes so it would hit the time window when data is supposed to move from proxy to server. Works at least for now.