I see... Thanks. I'll try that!

Update: I got it! Your tip definitely helped!
Thank you!

You're applying sort twice, and that's the problem (the final result is the same as chaining two sorts as I wrote before). Make a single sort callback function.

Probably your sorting is wrong as sort isn't stable in javascript and in some environment gives one result and in another environment you get another result when applied twice with different callback functions. Don't chain two sorts.

I am having a similar problem. Locally my solution seems to work. I get the tests to pass but on the web the results come slighty differently. Any hint? I'll post my code as a spoiler in the next comment if somebody can comment, it would be very much appreciated.

Please don't post solutions in discourse tab, that's what solutions tab is for. And as you probably figured out already, your previous solution was indeed too slow, and also incorrect :P

In future, please format your code properly when posting code blocks.