Was able to place memory I should not have

Hi!

It's likely that you'd had this route planned for a while, then left to get more memory fragments, and in your absence, the Essence island spawned. As it has no connecting bridge, it makes you unable to place the planned memory there. I understand that can be inconvenient, but to avoid potential shenanigans, it's important that players not be able to block reward islands with planned pieces.

I hope this clarifies.