Merck Spin-off of Organon & Co did not create an account - Why

An odd choice, in my opinion, but so be it.  But it is then up to you to create that Organon ACCOUNT in addition to creating the Organon security which you said you did.

The corporate spinoff action will create the spinoff (Organon) in the same account that holds the original security (Merck).  If you did the spinoff correctly, that is where you should be looking for the relevant transaction.  In that originating account, you should find Add Shares transaction(s) for the Organon security.  To correct the issue to your way of operation, you would simply MOVE (Rt-click, select Move) those Add Shares transactions to your newly created ORGANON Account.  

BACK UP your data file before making such changes - just in case.

No, I do not work for Quicken (those folks are identified as employees or moderators).  But I have managed to spend hours on this community and its predecessors.  But even with that, what I offered above is more about my 30+ years of experience using the program for myself -- from DOS days as well.

This community can be inefficient to get around, but asking questions with as complete information as possible (like you did), can be really helpful in getting realistic responses.  Most of the users and the superusers in particular try to be as helpful as possible.  We've all been through lots of trials and some errors with this program ourselves.  And we've seen people use the program in lots of different ways.   

A specific account for each security can work for a small portfolio, but after all these years, I have over 1000 securities I've used or followed.  Your approach would be a nightmare for me.  One of the basic mantras preached around here is to have Quicken accounts model or follow the real world account structure.  But again as noted, people find approaches that work for them.    

I take it you then got your issue worked out to your satisfaction,

OK, so I am not clear on your "original setup error".  So some questions and assumed answers.

Before going much further, make sure you have a good backup available to be able to recover with - just in case.

I am going to lay this out in a straight from-the-beginning approach.  You may need to do some deletions or adaptations to apply this to your current file state.  The gist will be:

• Create the Organon Account
• Do the spinoff in the Merck Account
• Move the Organon transactions from the Merck Account to the Organon account.

See this discussion in particular for comments about the screenshots -- https://community.quicken.com/discussion/7894737/merck-spinoff-of-organon-thread-for-all-related-questions-comments  

Try as I might, I can't seem to get this to a bullet-point list.  The problem I have is not knowing where you are now, nor where you were June 3 when this spinoff occurred.  Below are my basic thoughts.

1. You can create the Organon Account (your preferred setup) to go along with your Organon security either before or after you use the Corporate Spinoff action.  Creating the Organon account should be straight forward.  Create it with nothing in it, no securities, no cash.  It should have a $0 opening balance as of June 1, 2021 (any time before June 3).
2. The Corporate Spinoff action should work in the Merck Account for the Merck security as long as that Merck account is NOT a single mutual fund account (I expect that to be the case).  Also, that action cannot spinoff Organon if Organon already exists in your data file under that name.  There are at least options to address that possible issue (delete the existing or spinoff a different Organon).  
3. My opinion is the basics of the Corporate Spinoff are in the discussion to which I just provided a link.  This screenshot comes from there.  Therein, you might choose to use the post-spinoff prices I cited (73.91 for Merck and 37.00 or 36.998 for Organon), or you might choose to use different values to match your broker's generated basis values.   You might choose to delete the generated MiscIncX transaction or you might choose not too.  If you have multiple lots of Merck, your Merck basis per lot will likely be different than your broker's data.  You may choose to edit those values or you may not.
4. Once you have the Merck and Organon securities properly represented in the Merck Account and have created the Organon Account, you will want to move the Organon transactions in the Merck Account to the Organon Account.  
5. Make a backup!
6. Right-click anywhere in the Merck Account, choose the Move Transactions option.Choose any one Organon transaction.  Make sure the Select All ... box is checked.  Set the Move to account field accordingly.  Click on Move.  Click on Done.   
7. All the Organon transactions from the Merck Account should now be in the Organon account.  Add in any other applicable transaction (subsequent dividends) or move the from another account.

Those should be the basics, but I hope you see the various options, choices and decision points that also come into play.