I have a very strange problem and I would like to find a starting point to solve it.

The problem appears on my laptops with Ubuntu (16.04 and 19.04) when I turn on VPN (network-manager-vpnc) **but only on my parent's WiFi**. And that is a super strange thing to me. When I switch to tethering on my phone then everything (except very weak GSM signal:]) is fine. Moreover it seems that problem is only with HTTPS connections. curl hangs on TLS:

```
$ curl https://www.onet.pl/ -v
* Expire in 0 ms for 6 (transfer 0x55cd601785c0)

... <Expire in... repeated many times>...

* Expire in 0 ms for 1 (transfer 0x55cd601785c0)
*   Trying 213.180.141.140...
* TCP_NODELAY set
* Expire in 200 ms for 4 (transfer 0x55cd601785c0)
* Connected to www.onet.pl (213.180.141.140) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*   CAfile: none
  CApath: /etc/ssl/certs
* TLSv1.3 (OUT), TLS handshake, Client hello (1):

```

But when HTTP used:

```
$ curl onet.pl
<html>
<head><title>301 Moved Permanently</title></head>
<body bgcolor="white">
<center><h1>301 Moved Permanently</h1></center>
<hr><center>nginx</center>
</body>
</html>

```

it returns a response.

Any idea what may be wrong? Please let me know if you need more info to help.