Whenever I click the portal to go to a random biotope, it keeps on telling me that I "can't enter this biotope". All the other biotopes work, though. I dont know why it's doing this, it's never happened to me before? I tried it out on both my phone and laptop, still doesn't work.

I have screenshots I will post later on, my laptop's battery just died and the files are on it :)

Thank you for reporting! Yes, there's really such a problem with random option, it's easy to reproduce. It must be fixed now. Sorry for the inconvenience.