I made a custom dirt block that is be able to grow grass on it's top if is air at Y+1. The procedure was put in "On block tick update". I also made a biome that has the block. Everything was fine but I tested if the procedure works - failure. I went to my biome, broke custom grass block and under it was my custom dirt block. I waited to see it change into a grass block and nothing happened. There's nothing wrong with my procedure cuz I tested it by manually placing the dirt block and it worked. I hope it will be fixed.