While OnePlus 3 and OnePlus 3T have been getting software updates in regular intervals, the same cannot be said about the OnePlus 2. OnePlus has already announced that the OnePlus 2 would never be updated to Android 7.0 Nougat.
The reason for not introducing Nougat to OnePlus 2 was also stated, "When we built the OnePlus 2 we didn't have the software infrastructure team in place we do now." However, we think that the phone's hardware would probably be able to run the new software without any glitches. Whatever may be the case, OnePlus 2 owners finally have something to look forward to.
OnePlus has just rolled out a new OxygenOS update for its OnePlus 2 customers. Carrying the version number 3.5.9, this update fixes a particular issue with the handset that has been bugging the users for a long time.
As some of you may know, the OnePlus 2 has an annoying issue with the VoLTE reception, wherein the VoLTE option was not visible in the connectivity suite of the smartphone. This problem started after the device received the OxygenOS 3.5.5 update. Even though OnePlus assured the users, the VoLTE reception issue wasn't solved by previous OxygenOS 3.5.8 update.
Apparently, the latest OxygenOS 3.5.9 update will fix the VoLTE bug.
However, you should keep in mind that OxygenOS 3.5.9 is still based on Android 6.0 Marshmallow, so there wouldn't be any improvements in that area.
Meanwhile, OnePlus also released OxygenOS Open Beta 19 and OxygenOS Open Beta 10 for OnePlus 3 and OnePlus 3T respectively.