Auto flower stalled flower?

don't worry, in my opinion, everything is fine, some seeds can take even a few weeks longer than what is written. if you want to get an idea you can compare it with my .. royal gorilla and I noticed that at the 8th week they have flowers of the same size, mine then finished at the 13th week, I remember that the same doubt came to me, but if you go to have a look on my diary it will be clearer to you. in my opinion your plant grows very well, so don't worry, just keep an eye on the pH, but I think that is not what it takes and its material time, which for some seeds sometimes takes a few more days, but I see that yours is big enough and for me and that is the reason. you will wait a few more weeks but trust it will be worth it. good luck for the harvest. bye