Steps to reproduce:
-Go on creative and get as many bedrock, grass and beds as you want
-Use the bedrock and place it on grass (make a big square)
-Make a hole (Just destroy 1 block of bedrock)
-Change back to survival
-Place grass in the hole (small grass)
-Place a bed on the grass and 1 block of bedrock will destroy
YOU MAY ALSO FOLLOW THE SCREENSHOTS I TOOK