Fyp Glitch?

Can anyone tell me why TikTok is behaving this way? I was scrolling yesterday and I come across a video of someone who has blocked me, I was confused at first because I shouldn’t be seeing their stuff since they have me blocked but yet it came up on my fyp. They have had me blocked for a month and 1/2 and the video was one day old and the account still said account not found. Is it because they unblocked me and re-blocked me and the video slipped into my fyp or is it a TikTok glitch in general?