Did you know there is a piece limit that can be placed in your camp?
I was having trouble placing pieces of furniture in my camp. The pieces I was trying to place were able to fit in a 1x1 block and I had more than enough room. The message kept popping up, "There's no room to place this item." It frustrated me until I asked myself "Is there a limit to the number of items that can be placed?" Sure enough that number is "40".
I found it on this site: https://www.imore.com/animal-crossing-pocket-camp-tips-and-tricks?amp. I verified that by filling up my camp site and then deleting each one. It is 40.
I don't understand why there is a limit. As long as you have the space, you should be able to put what you want. I hope they fix this in the future.