immediate termination

Hey guys! i was hired and trained in a bakery as sales assistant and bake, it was the first branch of the store.

however, I was sent to another new store, just opened last March 27. There, I had a different manager.

We were able to continue selling and was doing well especially on the super busy first weeks. We were working overtime (Im a full timer) I was able to deliver things, perform well like anyone should be, however, the manager keeps on picking on very little things to us.

She keeps on putting me on rosters on 10pm closing, and 7am opening the next day.

She keeps on hiring people who only knows how to do sales, and does not even know how to bake.

She has a lot of things to improve, while I do too but I am aware of the things I should do.

She cut me on hours (i'm over 38 tho but that was not my choice) just because she scheduled alot of staff that day.

I was never late or absent.

When she brings up things, I try to change my ways. I have a strong personality that I don't tolerate anything that can harm our products, so I always ask for her suggestions.

Yesterday, she went cold to me, then after going home, outside my hours shift, she just emailed me saying she was terminating me ASAP.

I am still on probation and ofcourse, she can do that. But I can't find any reasons why she would terminate me, on my 4th week.
Workmates were shocked because we used to work together and states that this is unfair.

I know I can't change anything. But it is just so unfair.