Cross-corelation of 2 Matrices

I have 2 x matrix of large data set and I want to find the similarity between the two matrices. So I decided to use cross-correlation function. Now the results are as given below and I don't have any explanations for such results?

a. When the entire length of two matrices are composed of one constant value (suppose 1) and are equal. The highest cross-correlation found by the function is 0.8547 and the row and column coordinates of the best match is 131778. Shouldn't the cross-correlation be 1 throughout the length of matrix instead of 0.8547 at 131778.

b. In another case highest cross-correlation found by the function is 0.35 and the row and column coordinates of the best match are 277854, however the total length of the matrix is 135808.