Crestle AI - cannot find session

Hi! I am new to this course.

When I first set up Crestle AI, I was able to successfully open the Jupyter notebooks linked with the course.
However, when I visited the Crestle AI site and started the session WITH GPU enabled, then follow the link, I get the following error. Is there something wrong with the link, and is there any way for me to find out? I cleared my cache just in case and even tried a different browser, but I seem to be unable to find the session.

I would really appreciate any help!