[2020] Failed to replace foundations

Hey @Delorre

Welcome to our community.
Flotsam building pieces can only be upgraded to Stormglass pieces.

Hey @Delorre

This is as intended due to current technical limitations. It was not mentioned in the patchnotes as it is not an issue or a fix. Like any other feature or content coming in the Isle of Siptah, it was not directly specified in the patchnotes.
If at some point we overcome the technical limitation, we’ll look into the possibility of making these building sets work akin to the other sets, but for now this is intended.