Repeated Puzzles

I am a new to chess.com and a beginner at this game, I am trying to improve my tactical game play by solving lot of puzzles but however I did observe that out of all the puzzles I have come across about 40% of them are repeated ones.

Is this a known bug? Can this be fixed? How do I avoid this?

There are over 500,000 puzzles, but they are spread across the rating spectrum. It's possible to get repeated puzzles but I don't think I've seen that many of them repeated and certain not in most sessions. 

One puzzle that repeats very often for me (it was twice in a row today)

https://www.chess.com/puzzles/problem/2011022

https://www.chess.com/puzzles/problem/2028304

Looks like different puzzles but solution is the same/identical

Thematically the same but different material on the board