I've not tested this with other NPC, as it was my first time disconnecting after chatting with the NLC Taxi. Kindly close this thread if it has already been reported. To replicate the bug: 1) Chat the NLC Taxi (or any NPC, if this isn't a NPC script bug) 2) Press Enter 3) Press Left button twice (highlights Back) 4) Press ESC 5) Wait a few seconds and you'll disconnect
I'm used to navigating through the NPC using arrow keys to go Next and so on, but I accidentally pressed the left arrow twice which highlighted the Back option which brought the NPC back to the first dialog, and by habit I would usually close the NPC chat by pressing Esc and then re-chat the NPC again.
You don't even have to press esc if i remember correctly, just clicking the back arrow will do the trick