Posted December 01, 2017
Sorry to bump this, but I believe I might have figured out when this bug happens.
When after clicking "Post my message" the window gets stuck, but your message gets posted nonetheless, then the last date sets to Nov -1, until a newer properly created thread corrects it.
When after clicking "Post my message" the window gets stuck, but your message gets posted nonetheless, then the last date sets to Nov -1, until a newer properly created thread corrects it.