As the others say, you are clearly having a sorting and a description that does not match.
Whether you agree with it or not isn't relevant.
You are factually wrong.

I added it in the description.

The sorting criteria you mention are ambiguous at best.

In the result, substrings will be in decreasing order of their length and when they have the same length sorted alphabetically

In order to correctly interpret this, one needs to know that

substrings

refers to the '/' delimited peices of the final result. This is not explained anywhere. I (and others, as seen in the comments) interpreted 'substrings' to mean the string of repeated characters. These repeated sequences are the basic units of the problem and therefore lend quite well to filling the undefined role of 'substring'.

The sorting criteria are all in the description:

In the result, substrings will be in decreasing order of their length and when they have the same length sorted alphabetically

It is easy to say, the problem is that it is a bit more difficult to do. Nevertheless thanks for your post.

Edit:

Many comments were frustated...

but many comments said they had fun.
Cheers

I don't understand what agreement has to do with it. If there are more sorting criteria that are not mentioned in the description, then it is objectively an inadequate description. That some number of people pushed through it (arguably due to reading the comments, as I am now), that does not mean that the description is adequate, it just means that people either figured it out (i.e., wasted lots of time, as you can see from some of the commenters here) or are aware of these sorts of issues on Codewars and fortunately chose to read the discussion first.

It's remarkable that you would claim the description is "perfectly" understandable, considering how many comments here were frustrated and confused by the sorting description. And as for proposing a better description the one here in the very comment that you are replying to is already better than the one in the Kata. Jtauri's is also good. The problem isn't that people aren't providing you with better descriptions, the problem is that you're ignoring them.

I don't agree with you and I am sorry for that! You can see that 1530 guys passed the kata (which is pretty good for a 4 kyu kata) so it is perfectly understandable and doable.
Nevertheless you can propose a better description though for the time beeing I find your explanation very unclear.
Thanks for your post.

Sorting instructions definitely need to be clarified. You first have to sort for the count of the particular letter, then by the string which had the highest count, THEN alphabetically. As its written now you only have to sort by the count of the letter and alphabetically if the count of the letter is equal between the two strings, which is incorrect