No, you are supposed to fall through some of the ruins in the sea level, it is part of the puzle! Aside from that:

I found the shroom and went to the psychedelic area and go through the gate but are NOT transported - I stay in the psychedelic area. How do i fix this, please?

I started playing this game today, in VR on Quest 2 via Quest Link. I'm bumbling my way through, and making some progress. I don't know what chapter I'm in, because I don't know how to tell. I went through the dark caves, picked up the ball, worked my way down to the waterfalls area, and turned day to night. My problem is not knowing how to properly save & exit. The only method I found is to hold down the grip button on the right controller, which takes me back to the menu. But when I resume the game,...

Really simple. Right click on the icon of Mind on your steam library > properties > betas > old_mind Profit :)

TL;DR As you may know some people reported problems with gamepad, keyboard and mouse using the Oculus Rift. We have been looking for a solution to this problem, and we are sorry to say we will not be able to fix it for MIND. “Thankfully”,