Intuitive Surgical Inc. (ISRG), the maker of a $1.5 million robot surgery system, told doctors that friction in the arms of some devices may cause the units to stall, the second warning issued about the company’s products in a month.

The company sent an “urgent medical device recall” Nov. 11 alerting customers of the issue, which affects 1,386 of the systems worldwide, the U.S. Food and Drug Administration said in a Dec. 3 notice on its website. The stalling may result in a sudden “catch-up” if the surgeon pushes through the resistance, the agency said.