Why did Dmitry Andreikin and Aravindh Chithambaram withdraw from the Sharjah Masters 2025?

Why did they? Weren't they confirmed participants of the 2025 Sharjah Masters before? Now they are not listed on the chess-results page.

https://www.chess.com/events/info/2025-sharjah-masters - here the participants list includes Aravindh Chithambaram and Dmitry Andreikin

https://chess-results.com/tnr1100164.aspx - here the participants list does not include Aravindh or Andreikin.

Why is it like this? I also remember seeing Andreikin and Aravindh on the chess-results participants list for the Sharjah Masters 2025 before.

Also, why does the number of participants keep changing? It was 77, then I heard the "full" 80 players announced, only then later to see 86 players, then seeing 82 players.

What? Aren't their 80 players?

Someone please help me know why this is the case.