In other words, it's not sufficient that you be good at algorithms. You also need to get a panel of interviewers with whom you gel well. What interviewers you get at a company, is not in your hands.
You can try a few things:
1. Do mock interviews with experienced interviewers.
Get used to being judged. Repeatedly.
2. Don't interview with the agony of getting a job. Just go to solve the problems.
Listen to this: https://www.youtube.com/watch?v=v1WiCGq-PcY
3. Interview at companies that bias towards take-home tests.
If you haven't already, then try triplebyte.com. They can help you find such companies.
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I make these observations based on my experience running a successful bootcamp for interview prep (http://interviewkickstart.com) and also being an early engineer and a hiring manager (Director of engineering) at Box prior to that.