I found a very suspicious account that participated in the last educational round:

utkarshkryadav https://mirror.codeforces.com/submissions/utkarshkryadav

This account has a history of weird submissions patterns and solving tasks in a weird order. In the last round, "he" solved A then D then C then B, solving D in 2 minutes and C in 1 minute (!)

In round 1048, "he" solved D then A then C then B. In many rounds, "he" always makes an incorrect submission on A at the beginning, solves something else, then solved A later. "He" also makes a lot of submissions in quick succession.