Download Station with vpn client - problem

[pajratus]

Hi All,
I have a TS-431+ running current release QTS 4.2 and beta 4.2.1.
I connect the DS to the internet via the VPN client using a PPTP connection (Cyberghost premium).
it worked very well for a few months . But for a long time (I did not change anything in the settings) when I start downloads (torrent) they initially run OK but after some time they all completely stall and stop both upload and download.
If I disconnect and connect the VPN connection they start up again. and they stop after some time again (I checked already different VPN servers - the same)

Any suggestions for how to prevent the transfers from stalling?
Now to download the file 1 Gb I have to disconnect and turn on the VPN connection several times

thank you very much for your answer