The bug

After a piece of redstone dust is right-clicked by the player and then redirected (for example by a repeater, a detector rail, a target block or another redstone dust) and then the redirecting object is removed, the redstone dust forgets its dot state, which is both annoying while building contraptions and greatly reduces possibilities with the redstone dot.

How to reproduce

1. Place a piece of redstone dust.
2. Right-click it to turn it into a redstone dot.
3. Redirect it using any of the following:
   • Lever
   • Tripwire Hook
   • Button
   • Pressure Plate
   • Trapped Chest
   • Target Block
   • Detector Rail
   • Comparator
   • Redstone Repeater
   • Redstone Dust
   • Observer (red side)
   • Redstone Block
4. Remove this block.
5. You will notice the redstone dust has forgotten its dot state and instead has reverted back to a redstone cross.