What potential issue is the user facing with the PHP code related to minimum number validation?

The potential issue the user is facing with the PHP code related to minimum number validation is that the comparison operator used is incorrect. To fix this issue, the user should change the comparison operator from ">" to ">=" in order to include the minimum number as a valid input.

$number = 5;
$min_number = 10;

if ($number >= $min_number) {
    echo "Number is valid.";
} else {
    echo "Number is not valid. Please enter a number greater than or equal to $min_number.";
}