Microsoft account not sharing DLCs correctly for Destiny 2

Thank you for contact us! I'm Anderson, an Independent Consultant and a Microsoft user like you.

Good afternoon

Unfortunately, you must consult the developer of destiny 2, they are the ones who release updates within the game.

If it wa purchased on your brothers account DLC does NOT TRANSFER between platforms

Destiny 2 add-ons cannot be shared or transferred between platforms, including between Destiny 2 on the Microsoft Store and Xbox consoles. For more information, please see our Cross Save FAQ.

Silver will be shared across Microsoft Accounts on any Microsoft platform: Xbox One, Xbox Series X|S, the Microsoft Store, and the Xbox app for PC

Game share is only on consol

Keep in mind destiny has a new owner

Destiny dlc can't be shared. It is account based. Sorry

This wasn't true for every other DLC before Shadowkeep.

This is apparently a new approach that wasn't explained well to existing players who purchased DLC in the past.

The new approach diverges from past experience with Destiny 2 DLC.

Destiny dlc can't be shared. It is account based. Sorry

Here is the possible issue with your situation directly from Bungie (the publisher of the game)

Sharing Destiny Content with Multiple Accounts

Some platforms may allow players who own Destiny content licenses to share game content with other accounts on the system.

For information on how to access game sharing features, please see PlayStation Support or Xbox Support.

Players accessing Destiny content through the game sharing feature may not be able to access all DLC, add-ons, promotional items, or pre-order items for which the primary account owns the licenses.

Bungie does not support any issues with loss of access to items on accounts that are using the game sharing features to access Destiny content.

This was taken directly from the following website.

https://www.bungie.net/en/Help/Article/12458

So in short there are certain Destiny 2 DLC that is not sharable.