XF 1.5 Facebook Login Fail

While trying to login using facebook connect, it logs me in and then immediately redirects me to a logged out version of the forum. Here is a video of the occurrence. I do used a secured url for the forum.

Thanks for all suggestions!

Hello Mike, I just found exactly the same issue, but my updatable interval has already expired, so I can't download the 1.5.5, but this is quite a serious bug, if it is just about editing some simple source code, can you please suggest where and how to correct it?