Thanks for your quick feedback. (A bit of context : We do S / R every day and run PTlive every day as well, just not normally with VPN active)
You are right, S R works fine. I was "put on the wrong leg" by this message 
Which appears when a PTlive session is launched. It appears only once. The 2nd time one tries to launch PTlive, the message does not appear and PTlive is launched without a problem.
Maybe it is a timeout issues ?
Having clicked "Start session" this normally takes a few seconds to launch PTlive, but with VPN active it does not seem able to connect and produces the error message after about 120 seconds. So for me this problem is reproducible.
