Drum Machine Test 6 Failing

Tell us what’s happening:
Test 6 for my Drum Machine only intermittently passes. All other tests pass every time. I have spent most of the day trying every fix I can think of and every fix I could find on the forums here, StackOverflow, and even Reddit. I could really use some help understanding what is wrong with my project.

Your code so far
Here is a link to my project

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Challenge: Build a Drum Machine

Link to the challenge:

I assume you’ve fixed it? Because all tests pass for me.

That’s the thing, I intermittently get all 8 tests to pass. More often I only have 7/8 passing and test 6 is always the failure.