Fedora 25, pptp connects but not working, too many transferred packets

edit

After update to Fedora 25 one of my PPTP connections strangely works. Remote net is not available.

It is connected, successfully get remote net IP address. While connected nothing is available in remote net, but internet works fine. After a few minutes connection breaks by itself.

I've noticed strange thing, while pptp connection is on there are too much TX packets transferred:

ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1400
        inet 192.168.1.96  netmask 255.255.255.255  destination ___.__.___.___
        ppp  txqueuelen 3  (Point-to-Point Protocol)
        RX packets 10  bytes 172 (172.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9864041  bytes 5842982146 (5.4 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

In a 10-15 seconds it shows up to 5.4 GiB of packets. It grows very fast.

The same if firewalld is disabled.

I'm using Network-Manager to connect to pptp.

[root@c0rp ~]# lsb_release -a
LSB Version:    :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID: Fedora
Description:    Fedora release 25 (Twenty Five)
Release:    25
Codename:   TwentyFive
[root@c0rp ~]# uname -a
Linux c0rp 4.10.8-200.fc25.x86_64 #1 SMP Fri Mar 31 13:20:22 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Can someone help me to investigate the problem, please