Owners of the FreeStyle Libre 3, one of Abbott Laboratories’ flagship glucose monitors, received an email this week warning them to “disable automatic system updates on your iPhone” because the new operating system’s StandBy Mode and Assistive Access Mode “may impact your ability to receive time-sensitive notifications including glucose alarms and notifications indicating that alarms are unavailable.”

“Key Steps to Optimize your FreeStyle Libre System on iOS 17,” the email reads. “While our teams are working quickly to verify and confirm compatibility, we recommend that you disable automatic operating system updates on the smartphone using the mentioned apps. Please check the compatibility guide on myfreestyle.com before the new operating system is installed.”

Abbott is telling customers who have already upgraded to disable StandBy Mode, which activates the iPhone’s Lock Screen while it’s charging and placed on its side. They are also being advised to turn off “Assistive Access” mode, an accessibility mode for people with disabilities. Abbott says that this mode “will impact your ability to activate a sensor, modify your alarm settings, or receive glucose alarm notifications from our apps.”

Abbott writes on its website that failure to take action when users get an alarm, or failure to use the device “as instructed in labeling may result in missing a severe low or high glucose event and/or making a treatment decision, resulting in injury.”