In my Samsung Galaxy Tab a 7.0 there is no software update and it is still lollipop version 5.1.1,sir please resolve this issue and also volte is not working properly in this device and always missing,then i have to restart everytime to work it properly.
Please be assured and to resolve "network" issue please follow below given steps:
1. Check device in safe mode:- Power off the device > Press and hold the Power key for one or two seconds to turn on the device > When the Samsung logo appears, press and hold the Volume down key. To exit safe mode: Restart your device.
2. Check Network mode and set it to Auto Connect. (Settings > Connections> Mobile Network> network mode SIM1 or SIM2 > Network mode> Select LTE/3G/2G auto connect)
And as of now there is no information available regarding updated software version for your device. So, whenever there will be any update available of it you will be informed for the same.
If the issue still persist, kindly register your concern in Samsung Members app (Samsung Members app > Get help > Feedback > Error report/ask question). Note: Please send device log files within 15 minutes of issue occurrence along with the exact issue details.