Why was my model blocked?

Stolen Content: If someone reported that you were selling a model you didn’t create yourself or that your model contained material you didn’t create, CGTrader would issue a warning. They’d ask you to remove any infringing models from your profile. If you didn’t comply and another stolen model report was received, your account could be suspended.

Copyright Claims: If a company that owns a trademark or copyright filed a claim, CGTrader would remove all infringing models from the marketplace. Using brand names, trademarks, or copyrighted material in your model could lead to suspension. For instance, brands like BMW, Mini, and Lamborghini cannot be used without permission

Try to re upload it, if it goes down again contact support.

Might be the the slow auto moderation or some misunderstanding with naming, textures, etc.
Try to reupload it, if it goes down again contact support.