Pretty much the same thing happened to me a year ago, I was at an onsite interview, did really well 4 out of the 5 rounds, but 1 round I just completely choked

Pretty much the same thing happened to me a year ago, I was at an onsite interview, did really well 4 out of the 5 rounds, but 1 round I just completely choked some basic linked list question and looked like an idiot.