In C Console isn't waiting for second input while filling up a struct array with values?

Question

I've a big problem. I created a variable array with struct. For that I've used malloc and realloc.

But if I'm using scanf ,the console isn't waiting for a second input and is moving forward. How can I solve this problem.

#include <string.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

typedef struct {
    float feuchtewert;
    float temperaturwert;
    char zeitstempel[8];
} T_DHT22;



int main()
{
    int length = 1;
    T_DHT22 *messreihe = malloc(length * sizeof(*messreihe));

    bool weiterErstellen = true;

    while(weiterErstellen) {

        char c = 'n';
        printf("Weiteren Messwert erstellen? <y|n>");
        scanf("%c", &c);

        if(c == 'y') {
            length++;
            messreihe = realloc(messreihe, length * sizeof(*messreihe));

            printf("\nFeuchtewert: ");
            scanf("%.2f", messreihe[length].feuchtewert);
            printf("\nTemperaturwert: ");
            scanf("%.2f", messreihe[length].temperaturwert);
            //gets(messreihe[length].zeitstempel);

        }else {
            weiterErstellen = false;
        }


    }

    free(messreihe);
    //sort_and_calcAvg(messreihe, length);

}