Applying a custom function to every row in r

I created a function to calculate the rollmean of a row in a dataframe:

rollmean_circular <- function(x) {t(rollmean(t(cbind(x[9:10],x,x[1:2])),5))}

df <- structure(list(X1 = c(5L, 5L, 9L, 0L, 9L, 10L, 10L, 1L, 0L, 10L
), X2 = c(6L, 8L, 6L, 9L, 7L, 5L, 0L, 7L, 5L, 8L), X3 = c(10L, 
7L, 2L, 1L, 2L, 10L, 2L, 9L, 6L, 4L), X4 = c(6L, 0L, 9L, 1L, 
6L, 8L, 3L, 7L, 8L, 1L), X5 = c(0L, 9L, 8L, 3L, 1L, 8L, 3L, 9L, 
5L, 2L), X6 = c(0L, 10L, 9L, 10L, 3L, 1L, 6L, 0L, 6L, 9L), X7 = c(9L, 
10L, 0L, 10L, 10L, 9L, 0L, 1L, 10L, 2L), X8 = c(2L, 6L, 3L, 7L, 
7L, 9L, 8L, 9L, 1L, 0L), X9 = c(0L, 8L, 8L, 9L, 0L, 5L, 9L, 9L, 
4L, 8L), X10 = c(1L, 4L, 3L, 0L, 1L, 7L, 3L, 6L, 5L, 0L)), class = "data.frame", row.names = c(NA, 
-10L))

   X1 X2 X3 X4 X5 X6 X7 X8 X9 X10
1   5  6 10  6  0  0  9  2  0   1
2   5  8  7  0  9 10 10  6  8   4
3   9  6  2  9  8  9  0  3  8   3
4   0  9  1  1  3 10 10  7  9   0
5   9  7  2  6  1  3 10  7  0   1
6  10  5 10  8  8  1  9  9  5   7
7  10  0  2  3  3  6  0  8  9   3
8   1  7  9  7  9  0  1  9  9   6
9   0  5  6  8  5  6 10  1  4   5
10 10  8  4  1  2  9  2  0  8   0

What this function does is given a vector, it will append the last 2 element to the front and first 2 element to the back and then do a rollmean so there will not be any NAs at the front or back.

It works perfectly when I apply to 1 row of a df.

r = df[1,]
rollmean_circular[r]

  [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
1  4.4  5.6  5.4  4.4    5  3.4  2.2  2.4  3.4   2.8

However, when I use apply to apply this function to every row of my dataframe, it returns a logical(0).

apply(df,1,rollmean_circular)

logical(0)

Can I know what I am missing?

When I apply another function that gives the same output for a single row, it works:

stdize <- function(x, na.rm=T) {(x - min(x, na.rm=T)) / (max(x, na.rm=T) - min(x, na.rm=T))}

stdize(r)

   X1  X2 X3  X4 X5 X6  X7  X8 X9 X10
1 0.5 0.6  1 0.6  0  0 0.9 0.2  0 0.1

apply(df,1,stdize)

    [,1] [,2]      [,3] [,4] [,5]      [,6] [,7]      [,8] [,9] [,10]
X1   0.5  0.5 1.0000000  0.0  0.9 1.0000000  1.0 0.1111111  0.0   1.0
X2   0.6  0.8 0.6666667  0.9  0.7 0.4444444  0.0 0.7777778  0.5   0.8
X3   1.0  0.7 0.2222222  0.1  0.2 1.0000000  0.2 1.0000000  0.6   0.4
X4   0.6  0.0 1.0000000  0.1  0.6 0.7777778  0.3 0.7777778  0.8   0.1
X5   0.0  0.9 0.8888889  0.3  0.1 0.7777778  0.3 1.0000000  0.5   0.2
X6   0.0  1.0 1.0000000  1.0  0.3 0.0000000  0.6 0.0000000  0.6   0.9
X7   0.9  1.0 0.0000000  1.0  1.0 0.8888889  0.0 0.1111111  1.0   0.2
X8   0.2  0.6 0.3333333  0.7  0.7 0.8888889  0.8 1.0000000  0.1   0.0
X9   0.0  0.8 0.8888889  0.9  0.0 0.4444444  0.9 1.0000000  0.4   0.8
X10  0.1  0.4 0.3333333  0.0  0.1 0.6666667  0.3 0.6666667  0.5   0.0