While the issue does not appear to be widespread, some AppleInsider readers have reported seeing the issue first hand, saying the new connector is getting stuck in their Macs, cars and even dedicated chargers.
Apple's Support Communities has a thread dedicated to the problem, where miffed users have taken to posting their experiences with the problematic connector.
Forum members posited the design of the Lightning's USB plug is to blame, saying the pair of indentations meant to secure the plug with a host machine are too deep. The USB standard calls for these two "notches" to be built in to connectors to prevent accidental or unwanted removal of the cable.
Apple's 30-pin connector design (let) features shallow notches compared to the new Lightning connector (right).
Source: AppleInsider reader Richard via flickr
In most implementations, specially shaped leaf spring detents within in the USB socket hold the plug in place and allow for easy insertion and removal. However, if the corresponding indentations on a connector are too deep, the detents may extend into the plug past normal operating limits, essentially locking the plug in place.
Embodiment of USB protocol receptacle with detents highlighted. | Source: NTC Distributing
It is not guaranteed that the security notches are causing the problem, though the feature appears to be one of the main design changes from the legacy 30-pin dock connectors.
According to multiple Apple support forum members who contacted, the company is supposedly aware of the problem and will replace the cables for customers affected by the issue.