A lot of solutions are passing this due to insufficient testing. There is only one number in the tests and it's a 'pass', so solutions that remove all numbers from the input are passing because a null string counts as a palindrome.
Again with the 'tricky' argument list. Nothing in the problem said the function should handle matrix inputs, but you throw one in there just to be clever? Not impressed.
I thought the empty set test was uncalled for. Might as well add in numeric arguments if you're wanting to make a case for checking if your inputs are valid.
I don't understand why the checker is rounding the answers, nor why some implementers are rounding the answers. Maybe it's to avoid roundoff issues, which admittedly are an issue when testing equivalence, but any reasonable solution to the problem should be able to give an answer out to 5 or 6 decimal places.