The bug
When placing command blocks in certain quadrants of the world, facing a particular direction makes the blocks harder to place upwards. This does not happen with most other directional blocks.
How to reproduce
Create a new superflat world
Begin flying in creative mode
/tp -5 6 5 90 80
Place a piston
→ ✔ It's pointing upBreak it and place a command block
→ ❌ It's pointing towards youBack up five blocks, so your X coordinate is positive, then place another command block
→ ✔ It's pointing up
Notes
Blocks that work correctly:
✔ Piston, dispenser, dropper, barrel, observer
Blocks that work incorrectly:
❌ Command block
Whoops, I didn't realize this was a duplicate. Here's my video explaining it: https://youtu.be/yuJ7z_mpR_c