hun, i think it's the age, were having A LOT of trouble with A with the same thing right now.
We get out of the car and i get "i want to walk" so we let her walk, then i get "i want a cuddle" she kicks and screams if we try and put her in the trolley (she stands in the back) but then she's fine.

Some days she will go in the pram without a problem, other days she goes off her head at the thought.

Will be interesting to see responses, at the moment i stick it out, i put her in the trolley or pram whether she likes it or not, she tends to cry a bit and i go bright red with embarrassment but she eventually stops.