OpenVPN loses connection after some time

[TheOneAndOnlyChosenOne 0]

I'm running openvpn through this command:

sudo openvpn --config vpn.ovpn

which works. I can ping several websites.

After a while, I cannot ping anything anymore, including ip addresses. I can still ping an internal ip.
The openvpn command is still running.

After the Initialization Sequence Completed:

Quote

Sun May 12 15:58:59 2019 [XXX] Inactivity timeout (--ping-restart), restarting

Sun May 12 15:58:59 2019 SIGUSR1[soft,ping-restart] received, process restarting
Sun May 12 15:58:59 2019 Restart pause, 5 second(s)
Sun May 12 15:59:04 2019 NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Sun May 12 15:59:04 2019 TCP/UDP: Preserving recently used remote address: [AF_INET]XXX.XXX.XXX.XXX:443
Sun May 12 15:59:04 2019 Socket Buffers: R=[163840->163840] S=[163840->163840]
Sun May 12 15:59:04 2019 UDP link local: (not bound)
Sun May 12 15:59:04 2019 UDP link remote: [AF_INET]XXX.XXX.XXX.XXX:XXX

'Restart pause' happens at increasing intervals.

According to the man page:

Quote

OpenVPN to exit after n seconds of inactivity on the TUN/TAP device. The time length of inactivity is measured since the last incoming or outgoing tunnel packet.  The default value  is  0 seconds, which disables this feature.

So now I'm confused.