Scrivener unusable when connected to VPN

1.6.1.0 When connected to Checkpoint VPN, Scrivener takes over a minute to open, frequently locks up with “Not Responding” error. Keyboard takes nearly 10 seconds to catch up with typing etc. Completely unusable. Disconnect from VPN and it’s back to working normally. Files are saved to a local drive, but one that is synced to Windows with “user file redirect”, some form of Windows DFS. Backup is to dropbox.