Can I just pop in here with something, one of my current plants in my current grow is my first experiment with the 'auto' ruderalis crosses, it was sold as "Fast Bud #2", apparently derived from the original fast bud which sounds like you were growing.
I soaked her overnight on 16th June.
Planted her on the 17th June.
She broke the surface of the soil on 20th June.
They were 2-3" high on 21st June. They seemed strong and confident wee climbers.
On 30th June there was the first signs of the plant considering pre-flowering.
Today, 14th of July (3 weeks 3 days from breaking the surface), heres a picture of her I took today:
Finally starting to live up to its name. They claim 5 to 6 weeks flowering period, at first I thought that was horseshit, but tbh now I'm not so sure. I should point out that while its an autoflower, I grow them in my flowering room 12/12. That works, kinda voids the point of an auto, but I did it purely out of lack of space. Certainly the fastest I've seen a plant get its hairy nips out.
Also, what makes an auto an auto is its ruderalis cross genetics. Ruderalis are wild and remote, in other words they've evolved to be quite hardy, and also they autoflower by nature to aid their survival in more difficult conditions. In other words, the less you fuck about with them, the better, too much love will kill these plants. Give them the common basics, then leave them alone, they're probably the hardest plant to kill, so if yours are going badly, you may be trying too hard ... too much enthusiasm with 'more is better', always thinking of ways to make it more ideal ... nothing wrong with wanting to give a lot of love, but if ruderalis genetics are in there, they're independent feminists... lmao
Of course, that doesn't mean they're bombproof, my other auto experiment (Black Jack Auto), one was sickly from seed, the other is growing well, so it all comes down to the quality of seed you get and of course, old fashioned genetics at the end of the day.