in java people are able to glitch through the bedrock in the nether being able to create a portal making it very easy to make a nether hub. and i do believe that this was an added feature to 1.15 java edition, it isn't just a bug on java. however, in bedrock edition, you cannot glitch through the bedrock, and when trying to place a block above bedrock in creative, it filled my screen with error messages saying "cannot place block above the 180 block limit".