Why has my baby started yelling and screaming at 7-1/2 - 8 weeks?

My baby was always fussy but the past week, I don't know what happened. From around 4pm to 9pm she will be very fussy and be screaming a lot, for really no reason. Feeding her more makes her calm down, but I know how she acts like fed. This is different. Also, during those hours, if I sit with her in the same exact position as when she stands, she will yell. Once we stand and walk, she's fine like its all good lol Then she will fall asleep later in the night

She is averaging around 6 hours a night the ever since 7 weeks began. Now we are at 8 weeks. She actually slept 7 hours last night. So the sleeping part isn't the issue. It's the early evening to bed time that she started crying and yelling

It's just the screaming and crying between those hours that I don't understand. It is like a switch flips on. The times before that, she is fine lol.

Is this some sort of growth spurt?

Thanks