I was able to tell if this was already reported once. If I spawn an item frame with wolrd#spawn() the frame often appears on the wrong block / a shifted location. To be exactly if x-coordinate < 0 at x+1, if z-coordinate < 0 at z+1. It does not help alot to correct this by adding (1, 0, 1) or anyhthing because the both location / blocks will be checked for free block faces and when one of them is not solid the typical IllegalArgumentException appears in the console.