So I found a bug. In viridian forest I got stuck by walking into the side of the cliff face
I just found the bug too when I was going through the forest again to get Drowsee after beating the Rockets. If you walk next to the cliff it just sucks you in. Luckily I had Abra on my 2nd playthrough so I just Teleported out.
Put me down for a third. Was trying to walk down the brown stairs.
So I found a bug. In viridian forest I got stuck by walking into the side of the cliff face