your text has to contain real newlines, not literally "\n" ("\" + "n") . The literal "\n"s in the assertion message are an artifact of the tests framework
also : remember to specify which language you are using when you ask for help ;-)

Sorry for not reviewing your wall of codem but 500+ successful python comlpletions suggests that the issue is in your code, not in the kata.

I also updated the python version to 3.8, although again, that was most probably not your problem.

"Indexerror: string index out of range."

Well, that's very likely coming from your code, so that's not a kata issue.

a few test cases yeilding incorrect answers

Care to provide an example? As in, what the input is, what result you are getting, and what result the test is expecting (or assertion message). Make sure you're looking at the correct logs, which appear above the expected result. Also, saying that 10/100 tests are failing is almost irrelevant because random tests are RANDOM, and we can't see what inputs you're failing at.

Please provide more concrete examples or this issue will be closed :/

PS: read this FAQ if you're having problems troubleshooting your code.

That must be a miracle, would you like to show us your code?
(with CORRECT MARKDOWN FORMATTING, please)