Chinese authorities summoned Nvidia Corp. to discuss alleged security risks related to its H20 chips, casting doubt over the domestic business of the world’s most valuable company weeks after co-founder Jensen Huang met senior officials in Beijing.

Nvidia earlier this month said the U.S. government is giving permission to sell its H20 microchip again in China — but now a Chinese regulator is raising a red flag.

NVIDIA has been called in by Chinese regulators over claims that its H20 AI chip poses security risks, putting billions in potential sales at stake.