White box in dock on startup?

Hey there NotTechSavvy0, 

At present, we do not believe that this issue is concerning, but it definitely isn’t expected behavior. That’s why we’re trying to correct the issue with your help. This is one reason we asked for you to test the issue while your Mac is in safe mode. From How to use safe mode on your Mac - Apple Support

Safe mode prevents your Mac from loading certain software as it starts up, including login items, system extensions not required by macOS, and fonts not installed by macOS. It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed.

You can check to see if any apps are loading at startup. If so, you can remove them all, restart your Mac, then add them one at a time, testing to see which may be causing the behavior you're seeing. This resource explains how:

Remove login items to resolve startup problems on your Mac   

Have a good one!

NotTechSavvy0,

Thanks for providing those additional details. Just to confirm, have you had a chance to go through the steps provided in the previous reply to test the issue in a new user account? If so, did the issue persist?

If so, another great way to isolate and troubleshoot the issue further would be to test the issue in safe mode. Safe mode can help to determine whether an issue is caused by software that loads as your Mac starts up. For steps on how to boot into safe mode, check out the steps below from the following resource: How to use safe mode on your Mac - Apple Support

How to use safe mode

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

1. Shut down your Mac.

2. Turn on your Mac and continue to press and hold the power button until you see the startup options window.

3. Select your startup disk, then press and hold the Shift key while clicking “Continue in Safe Mode.”

4. Log in to your Mac. You might be asked to log in again.

Intel processor

1. Turn on or restart your Mac, then immediately press and hold the Shift key as your Mac starts up.

2. Release the key when you see the login window, then log in to your Mac. 

3. You might be asked to log in again. On either the first or second login window, you should see ”Safe Boot” in the upper-right corner of the window.

After testing the issue in safe mode, be sure to go through the additional steps provided in the resource above that can continue to troubleshoot the issue whether it does or doesn't occur while in safe mode.

Keep us updated on the results.

Take care!

Hello NotTechSavvy0,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you have questionsa bout a blank icon in your dock. Does it remain there or does it disappear? Does this happen in another user account?

Next, what we would recommend, is testing this issue in another user account. What we need to do, is log out of your current user. Log back in under another Standard or Administrator account and see if the same issue occurs there. This way we can tell if it is an issue with your user account, or if it is system wide: Set up users, guests, and groups on Mac - Apple Support

"Add a user

1. On your Mac, choose Apple menu  > System Preferences, then click Users & Groups .
2. If the lock at the bottom left is locked , click it to unlock the preference pane.
3. Click the Add button  below the list of users.
4. Click the New Account pop-up menu, then choose a type of user.

• Administrator: An administrator can add and manage other users, install apps, and change settings. The new user you create when you first set up your Mac is an administrator. Your Mac can have multiple administrators. You can create new ones, and convert standard users to administrators. Don’t set up automatic login for an administrator. If you do, someone could simply restart your Mac and gain access with administrator privileges. To keep your Mac secure, don’t share administrator names and passwords.
• Standard: Standard users are set up by an administrator. Standard users can install apps and change their own settings, but can’t add other users or change other users’ settings.
• Sharing Only: Sharing-only users can access shared files remotely, but can’t log in to or change settings on the computer. To give the user permission to access your shared files or screen, you may need to change settings in the File Sharing, Screen Sharing, or Remote Management pane of Sharing preferences. See Set up file sharing and Share the screen of another Mac.

1. For more information about the options for each type of user, click the Help button in the lower-left corner of the dialog.
2. Enter a full name for the new user. An account name is generated automatically. To use a different account name, enter it now—you can’t change it later.
3. Enter a password for the user, then enter it again to verify. Enter a password hint to help the user remember their password.
4. Click Create User.
5. Depending on the type of user you create, you can also do any of the following:

• For an administrator, select “Allow user to administer this computer.”
• For an administrator, select “Allow user to reset a password using Apple ID.”
• Use Sharing preferences to specify whether the user can share your files and share your screen.

For information about Apple’s privacy policy, see the Apple Privacy Policy website.

If your Mac or Magic Keyboard has Touch ID, a new user can add a fingerprint after logging in to the Mac."

We hope this helps.

Cheers!

Understand, we are all working Remotely from all around the world. 

Therefore, we do not have the On-Hands experience the User ( you ) has with this computer.

The next best thing for us to having a semi - actual On-Hand experience  with this computer is to follow the steps below

Download the Application Etrecheck directly from the Developer. 

The application is free or paid from added features. 

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Did the User use Reinstall macOS from the Recovery Mode ?

This would only perform an " In Place " Installation which would replace any corrupted or missing elements of the OS without touching Personal Data, Preferences and Setting.

Or, has the user Erased All Content and Setting offered in Monterey on M Class Computers and then Reinstalled macOS.

Thereafter Restored from a Time Machine Backup from a time when the issue was present ?

Thanks for trying those steps for us, NotTechSavvy0. Please let us know how that goes. We're here to help get this issue resolved together.

Thanks and take care.