So I found out about this glitch just today. I saw that most of the latest console runs are from around end of February, and when trying it, I'll hit the loading screen where I should go into the lab, but instead I just get put back in the room with the initial window I climb into.

So am I doing something wrong, or has it possibly been patched?

If it makes any difference, I'm on Xbox One

No it hasn't been patched, you must have not jumped at the right time or angle.

I did get it to work eventually, I realised I was jumping a bit too early, so I would just end up back at the beginning every time.