Just now, i have been disconected due to inactivity after summoning Thunderbird for the second time, before i even spoke to it. Now, even after i logged back in, I am unable to speak to Thunderbird, and as such, I am unable to finish this story quest.
Thanks for the advice, but I'm gonna have to contact support for help, since Thunderbird just sits there, and my person still is unable to get though to it.