I can't really reproduce this. Does it persist after restarting the game?
If I reload my save it's still a problem, yes. Only for that save file. This doesn't seem to happen on my other save file.
I did manage to pick them up, but I had to tear down a wall to get to them. So its not an item problem. They are pick-up able still. I made sure to reload test pick them up from the left and right with no problem. It's only from the bottom I can't pick them up. Which means it's probably a range issue.
I suspect it might be possible to just barely place an item out of pick-up range if placed just right, so when I placed these furniture items down from inside the house as far away as I could, I managed to place them just out of pick-up range.
3 days ago(+1)
I see what you mean now. If placed this way, there's a collider on that tile, and the pickup range is too short to reach it. Will fix.
Pick-u-able.
Not Pick-up-able. I was able to do this twice after a few tries.