Can someone tell me what the green ball is in the ...

Calyx ! Normal thing😁

It’s an ovum. The pistils are attached to it. Once the pollen reaches the pistils or “hairs” chemical reaction from the hormones in the pollen causes the seed to fertilise and “grow” in the calyx. This “pre-seeded” bud is typical of autos, and you won’t find much info on this... but from my own experience I’ve had loads with this. They typically just enlarged. If anyone’s interested to check if they have them too. Just pluck off a few developed pre-flowers off the main stem open them up have a look. Peace

It’s just a swelled calyx. Nothing to worry about.

Hi @itsmyusrname ! This is probably just the calyx but to ensure you're not having a pollinated plant I would recommend to touch the ball and check if it's hard or soft. If it's hard then you probably have a seed building up, that would mean your plant was pollinated somehow. Hope this helps, keep us up-to-date and good luck with the last days!

It's a swelled calyx, they look like that at the end of flowering. It's also where seeds would be if the bud were pollinated.