auto deduction fails for the array of const char*

constexpr auto TEST1 = "test1"; is deduced as constexpr const char* TEST1 = "test1";

whereas adding an & to the above statement

constexpr auto& TEST1 = "test1"; deduces the expression as constexpr char const (&TEST1)[6] = "test1";

What I don't understand is that the type deduction fails for the below expression:

constexpr auto FILELIST[] = {"one.txt", "two.txt", "third.txt"};

with error:

error: 'FILELIST' declared as array of 'auto'

Of course if I replace the auto keyword with const char*, it works fine.

constexpr const char* const FILELIST[] = {"one.txt", "two.txt", "third.txt"};

Can you somebody please help in understanding what am i missing here?