You are right that when initial queen is given as c3, then c3 should be in the answer.

In the description, 'c3' is an example of an input, and 'd8,a7,e6,h5,b4,g3,c2,f1' is an eample of some output, not related to the example 'c3'. But this is a valuable remark, the example probably could be clarified in this matter.

(for python)
I don't understand the instructions, if you fix a queen position, in the solution should be the initial queen fix.
For instance, if the fix queen is c3, the solution shoud be a.,b.,c3,d. ...
In the instructions says for c3, the solution is d8,a7,e6,h5,b4,g3,c2,f1 I don't understand why g3 and c2
Please, could you help me?

It's not mentioned whether palindromes should be case-sensitive (it isn't).

Numbers in JS are over the maximum number range, which is undesirable.

Actually, the kata should've just passed in a string in the first place.

The description is also not clear in the 1st ans 2nd instruction ~~ plus it seems to be a duplicate of a bitwise manipulation kata somewhere iirc ~

not enough tests: a solution reversing both parts can pass the tests as well as one reversing only the first half (as expected by the description)

Arg 10 must be encoded 0... Fixed

the output says "e10 is not a valid position..." But e10 is in the solution

"Is not a valid position" means that it's wrong and shouldn't be there.

Columns are marked with letters a-j, and rows with single digit from 1 to 0 (first row is marked with 1, ninth row is marked with 9, and tenth row is marked with 0)

Row #10 should have an index of 0 instead of 10, not an issue.

For input Size 10, mandatory position: g9, the output says e10 is not a valid position. Solution a1,b3,c6,d8,e10,f5,g9,h2,i4,j7 is not valid for size=10, pos=g9
But e10 is in the solution

Just figured out the print and the return weren't the same, sorry about it

Are you completely sure your output string does not contain any stray comma?

You're returning a string with a comma at the end, and you know it considering you slice the last character away when printing the result. Not an issue.

Are you completely sure your output string is formatted correctly and does not contain any stray comma or other characters?

If so, could you share your code? (remember about code formatting and spoiler flag)

When my program returns the string 'a2,b4,c1,d3', the test answers Invalid number of columns: 5, expected 4. In the 8x8 case, the string returned is 'a2,b5,c7,d1,e3,f8,g6,h4' and the test answers Invalid number of columns: 9, expected 8

Updated.