If you try to load a powered hopper to a non-powered location by the use of structure blocks, the hopper will be loaded as a ghost block (i.e. not visible, but still interacts with the player if the player tries to move into the block).

How to recreate:

1. Create a powered hopper
2. Create a bounding box with structure block corners with the powered hopper inside of the bounding box but the power source outside of the bounding box
3. Save the area
4. Load the save in a new area to a place where the hopper will be loaded in unpowered.
5. Observe your ghost block (except observing is difficult because it is a ghost block and thus invisible until you relog).
   Placing a block inside doesn't make the hopper appear though

This bug could very well be related to, or caused by the same mechanism behind MC-132200, but since it is created through a different path in a different scenario, I decided to open it as a new bug report.