Forza Horizon 4 - Lego Expansion Pack won't work

No, isnt free.

You can buy only
lego expansion or the
pack with the 2 expansions.

I would recommend forza horizon 4 lego expansion.

Forza Horizon 4 all the way! Especially with the recent LEGO Expansion.

If you have verified under "Manage" games that the DLC packs are indeed installed. A screenshot of the Forza Horizon 4 install and DLCs would help as well. Then you need to reach Level 20 according to the Forza official support page:

https://support.forzamotorsport.net...nd-the-LEGO-Speed-Champions-Expansion-in-game

"Please make sure you have completed the initial experience and have completed at least one race in Autumn to unlock the Expansions.

Forza Horizon 4 LEGO® Speed Champions is included with the Forza Horizon 4 Expansion Bundle and Ultimate Edition. It is also available as a separate expansion purchase. Forza Horizon 4 is required to play."

Also on this same page, you will notice "Submit a Ticket". This is the place to go for Forza support. They can look into any Forza specific problems.

The screenshot showing "included in this bundle" will only show a few as there are too many separate DLC items in it to list fully as there are 11 separate things in it:

"The Forza Horizon 5 Premium Add-ons Bundle includes the Forza Horizon 5: Hot Wheels expansion, Car Pass, VIP Membership, the Welcome Pack, and the second game expansion once it becomes available.
The Forza Horizon 4 Ultimate Add-ons Bundle includes the Car Pass, VIP Membership, Formula Drift Car Pack, Best of Bond Car Pack, and the Fortune Island and LEGO® Speed Champions game expansions"

But, as noted above, the DLC does not come as part of Game Pass Ultimate...you can buy the Bundle and play without owning the game (ie using the Game Pass version of the game)