Android 5.1 was meant to improve on the Android 5.0 update that is still slowly making its way on some of the newer Android devices. It was released to the Nexus 6 and other Nexus devices just last week, and it offers some great features. Fortunately, it is rolling out and on a fast track to be updated on all Nexus devices. Unfortunately, there appears to be a major bug that could cause some problems for Nexus users.
According to PC Advisor, Android 5.1 is expected to be "a large update, returning the silent mode missing from Android 5.0, improving system stability, RAM management battery management, and fixing sudden app closures, Wi-Fi problems and sound problems".
The 5.1 update will also include native support for more than on SIM-card, which works very well for phones with dual-SIM card slots. The user can also join Wi-Fi networks and control paired Bluetooth devices directly from the Quick Settings section of the notification bar. Then there is High Definition voice calling, via HD Voice, provided you have a compatible device like the Nexus 6 and a network like T-Mobile and Verizon.
There has been a report of a major bug on Android 5.1 for Nexus 5 users, according to Greenbot. It is an issue that began with the update of Android 5.0, and it has to do with memory resources draining. If you have a Nexus 5, you can diagnose this problem by opening the Settings, then going to Apps, and scroll to Running. You will then see if the system memory is eating up a lot of space.
TechnoBuffalo has also written about the memory problem, with a quote from Threatpost: "Users reported seeing their RAM bloat to over 1 gigabyte and leave as little as 150 megabytes free, before their phones ultimately crashed."
The effect on Nexus 5 users is that it slows the device down and occasionally crashes applications. So far, the temporary solution to this problem is to restart the device from time to time.
As far as when a more permanent fix is coming, Android police reports that a project member has stated that the 5.1 memory leak has been fixed internally. Now comes the bad news: "we do not currently have a timeline for public release".
In case you are wondering about when your Nexus device will be due for an Android 5.1 update, here is what Android Pit has listed as far was when Nexus users will get the 5.1 update. The T-Mobile Nexus 6 and the Verizon Nexus 6 should already have it, as well as the Nexus 5 that we previously mentioned, the one from T-Mobile, at least. As for the Nexus 4 and the Nexus 7, they should be on the fast track to receiving it. Also on the high priority list is the Nexus 9, as well as the Moto X, Moto G, and the new Moto E, but those Moto devices aren't part of the Nexus line.