Some Infinity Blade models do not appear when I launch

So I downloaded all the Infinity Blade packs, and began using them in my project. However, when I click “Play” they all appear fine, but when I click “Launch”, a few do not appear. Is there any specific reason for this? On the Marketplace, it does state that the Infinity Blade packs are compatible with 4.18, so I am a bit confused here.

Hello,

We’ve recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.

https://forums.unrealengine.com/unreal-engine/announcements-and-releases/1410408-unreal-engine-bug-submission-form

Thanks