I wrote it to Bugs/Technical issues but I will write it here as well.
The volcano on Ember Island has water inside and if you visit the island in nice sunny weather, you don't see that it glows. So my friend jumped into it and got instantly killed. We tried to build as low as we can but still, you can't reach the items. Now the items are there alone and sad.
My friend probably had one of the items you need in the control room so we can't continue either. 😕