Put the summary of the bug you're having here
What I expected to happen was...:
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What actually happened was...:
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Steps to Reproduce:
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2. ...
3. ...
Environment
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I noticed this too. Because regular f3 controls brightness on my laptop, I generally had to use shift + f3 for minecraft. Exploring the new snapshot, I noticed the graph doesn't go away, even persisting to the minecraft menu.