One week ago, November 13th, OnePlus start updating the OnePlus 2 phones with the latest OxygenOS update: 2.1.2. You can find detail about it directly on the OnePlus forum:
The good thing, at least for me, is the CameraApp performance improvements; the really bad thing is the DualSim "Ask Every Time" problem. Changes in dual sim settings are not persisted at all, which means, every time you have to specify the Sim Card you want to use for your call.
###Dialer Workaround To fix this problem when you are making phone calls from the phone you can just install a different dialer and use internal settings for the dual sim, ignoring the system one. You can for example use "True Phone Dialer" which adds some interesting functions for the dual Sim usage.
- SIM card selection by Contact or Contact Group
- Last used SIM for a contact (for example on a missing call you can automatically recall your contact with the SIM received the call)
- Dual SIM filter you can apply, for example, when you are linked to a bluetooth device
In the end is an interesting application to use even without the native setting problem
This Workaround is NOT working for a (my) bluetooth car System (Renault/TomTom). If you make a call directly selecting a number from the InCar "dialer", you are bypassing the "True Phone Dialer" and the SIM configuration will be read into the global settings. So it's a workaround which is not working in any situation.
I'll explain you later how you can automatically switch the phone settings when you enter in your car. :D
Hopefully a new update will come out soon to fix and allow us to go ahead working correctly with the dual sim functionality.