Some Apple Watch Ultra users complain about their smartwatch display getting too dim in low light conditions.

Multiple reports have been logged on social media as well as Apple’s official forum surrounding the watchOS 10 software update making the Apple Watch Ultra’s display difficult to read in low light. It’s believed that the device’s ambient light sensor has been affected by last month’s software update and has not been calibrated to match the brightness sufficiently.

Both the newly launched Apple Watch Ultra 2 and the original Ultra are affected by the glitch. The problem is immediately apparent when the user transitions from a bright room to a dark environment and tries to read the display on their watches. Others say that the Night Mode Ultra Modular watch face makes things worse. Also, attempts to manually fix the brightness via settings have largely proven to be unsuccessful. Only a future update should reset the brightness and readability to normal.