WeChat users who sued the Trump administration had “shown serious questions going to the merits of their First Amendment claim," the court said.
The order "adds pressure on ByteDance to find a buyer, while giving the U.S. government a chance to object if it does not approve of the choice."
The bans are set to take effect in 45 days unless the parent firms agree to sell the apps.
Instagram Reels launched in parts of Europe in June and is set to hit the U.S., Japan, the U.K., and Mexico next month.
Critics have brought up concerns around the app’s privacy practices and its possible ties to the Chinese government.