Matrix power function not working as expected

Greetings.
I try to solve matrix power function, but the result keeps showing zero matrix.
As shown in the attached notebook.
I look forward to your usual assistance.
Thank you.

The exponent in TropicalMatrixPower should be a positive integer, right? You are applying it to a matrix?

The first step in the iteration will give a zero matrix whenever the matrix a is positive:

Clear[a]
TropicalMatrixTimes[Array[a, {2, 2}], IdentityMatrix[2]]

To get a nonzero power, try a negative matrix a:

a = -{{2, 3}, {5, 7}};
b = {{4, 2}, {1, 2}};
TropicalMatrixPower[a, b]

Thanks for your response, Sir.
There is a base matrix and power matrix as shown attached.
Thank you.