Google has started rolling out Android Lollipop 5.1 to its line of Nexus devices, and while plenty of Nexus 6 and Nexus 9 owners appear to be, in general, happy with the update, owners of older devices, particularly the Nexus 5, are not as pleased.

Although Google's first major update to Android Lollipop was supposed to bring bug fixes to several problems that plagued Android devices upon the platform's release last year, the update brought major problems for plenty of Nexus 5 owners, including memory leaks, random reboots, and connectivity problems.

Android Lollipop's memory leak problem, which occurs when the system fails to release memory after an app no longer needs it, has existed long before the latest update. Back in November, owners of older Nexus devices running on Android Lollipop 5.0.1 began reporting that their handsets were taking up as much as 1GB of RAM until Lollipop eventually crashed. This typically happens when a user closes an app by swiping it away and the system eats up 100MB of RAM, or more, until there is no more memory left and the phone stops responding.

Google apparently noticed the bug last year and said it was issuing a fix in a future update, but the memory leaks are still present and seem to be more frequent on Android Lollipop 5.1.

Moreover, Google does not seem to think it is an urgent issue, since it will not push out the fix immediately.

"This has been fixed internally," said one Google employee. "We do not currently have a timeline for public release."

Other users have reported their Nexus 5 randomly restarting, even when they do not do anything except touch the screen. One user said his phone automatically shuts down when he presses the power button to lock or unlock his phone, a problem that occurred right after he installed the over-the-air update for Android Lollipop 5.1.

Wi-Fi and data connectivity are also causing headaches in other users. One user said he is having intermittent data connection since he updated his Nexus 5 last week. During the times he is able to connect to cellular data, he has to turn on Airplane Mode and restart his device. Another user complained that her Nexus 5 has stopped being able to turn on Wi-Fi hotspot and none of her devices can see the hotspot, even when the icon on her phone shows it is on.

Google currently doesn't have solutions to these issues, but one suggestion brought up in the Product Forums for users experiencing automatic restarts is to clear the phone's cache by going to Settings > Storage > Cached data then choosing OK when a dialog box pops up to ask to clear cached data. It might also help for some users to change the unlock option to swipe or other settings and clear up the phone's storage if it is low in disk space.

Other possible fixes include rebooting in Safe Mode to check if the power button works as it should. If it does, it means the problem is caused by a third-party app, such as a lock screen app or notification widget. If all else fails, reset the phone to factory settings as a last resort, but don't forget to back up important files.

A simple restart or removing and putting back the SIM card can clear up mobile data issues, so does tweaking with the cellular network settings, particularly the Access Point Name, but only if users know what they are doing.

These are only suggestions, though, and they may only temporarily work for some users experiencing the problems. Until Google acknowledges these issues and rolls out a fix of its own, it's best to keep Android Lollipop 5.1 away from a Nexus 5.

Photo: John.Karakatsanis | Flickr