I have been trying multiple ways to grow Nether Warts and I cannot get them to grow at all. With light, without light, with lava, in the nether, the overworld etc. I heard it takes a long time for it to grow and you have to be in close proximity so I worked on several things on my world roughly near the nether warts for about 3 hours and they never grew. So I then figured that maybe I just was not close enough So I was 1 block distance away from them and waited. Over a hour I sat there on my phone afk watching these nether warts directly infront of me never grow up past phase 1. I only ever found 1 other person who "reported" (reddit) this issue as they experienced it.  I then tried to move it to the nether where I sat for another 30minutes staring at it to watch it never grow past phase 1. AT this point it was almost 4am in the morning so I just couldnt stay awake any longer.  I read some people say it takes hours for nether warts to grow but this doesnt seem correct to me. Even with a hour passed they never grew.