Hey Growmie ...
Unfortunately, this does happen with autoflowers sometime, I've experienced once with a northern lights auto and currently, my original auto skunk from fastbuds is doing the same. They look as if they are going to start the flowering process and just never do, but the fix to it is to switch the lights to a 12/12 to help them flip over to flower. After a week of 12/12, they'll actually show that they are starting to flower.
Hopefully, this was helpful and remember ..."Happy Growing" and "Free your mind one puff at a time".