Thanks Riley! Adding info for your investigation: I did not copy the campaign. The player did not play (yet) concurrently with my, the GM, and the group. He had only Logged in the Game table to create character when he first joined the campaign a few weeks ago. The player lives outside the US. Around the time when he initially joined the campaign (again, roughly 3 weeks ago), I recall 2-3 other GM's posting Bug reports stating a similar issue (player persistently logged in even if their browser was closed). I'm not sure how the others were resolved. I remember thinking "Weird now it looks like I have the same bug they were asking about... I'll have to wait and see if this Player goes-away in a few days". At the time, a Community response was urging Players to click "Exit Game" (under settings in the VTT), rather than immediately closing the browser tab without using the Exit button, however this has not been confirmed/advised as a necessary technique by any Devs or Wiki Docs. It normally works fine even if people X-close the tab rather than Exit Game. My issue is resolved, added info in case anything points to a cause.