why the beanstalk climb is gone from the list?

Hi @shammaadiba - welcome to our wonderful community.  I am glad you could join us.  
All challenges and bonus games don't always reach every single player and unfortunately, we have no control over who does receive them. I will randomly get the bean stalk for a few days and then it will disappear and not show up for weeks.  Some people are not getting the Fantastic Five or the Daily Win.
If a certain feature does not appear in your game, all you can do is to make sure the app is updated and that the game is connected to your King or Facebook account. 
Just be patient because I am sure something else fun or interesting will eventually show up in your game.  The game studio is always testing new features and you could end up being one of the testers.
Make sure you take the time to explore the community and participate in the contests where you can win free gold bars.
Here is a helpful link for newcomers to the community.  It has a lot of helpful information: https://community.king.com/en/candy-crush-saga/discussion/258889/newbies-this-message-is-for-you#latest

@Candy_Crush_Addi - Welcome to our wonderful community.  I am a bit of a Candy Crush Addict too.  I have noticed recently that the beanstalk will appear for  a few days (it was there earlier today and now its gone) and then it will vanish for a week.  As I mentioned above - Not everyone has the same things - some people don't have the Daily Win sticker challenge (I didn't have for a very long time and now I have had it for several months).  Some people got the bronze, silver and gold bows etc.  I just go with the flow and enjoy what ever opportunities I have for free boosters.  

I honestly don't believe it is a glitch and they may just be adjusting the frequency of its appearance.    However I will check with the Community Manager and see what she says.  JellyJenny is on vacation - I have asked the person filling in for her).  However since they are all in Europe, I won't hear back until Monday.

@shammaadiba and @Candy_Crush_Addi - I heard back from one of the Community Managers and she confirmed that the studios are mixing things up on purpose so the Beanstalk won't be acting the way it has in the past.  It may appear and then almost immediately disappear.  Bottom line - it is not a glitch.