Android 6: disable roaming completely On my Galaxy J510 I have primary sim for calls and secondary for data only. Operator 2 doesn't have 100% coverage and provides data on its own network only.

However after losing signal, phone warns and a couple minutes later switches to roaming and disables data connection. After network is available, roaming is not turned off. My current annoying way to regain data connection is:


Settings 
Mobile Networks 
Network Operators 
SIM2 
Search Networks 
(wait ca. 30s) 
My operator


I want phone to stay in SIM2 not connected mode forever until home network is available - connection loss is not a problem cos I can answer calls via SIM1.
Thanks fo any ideas.
Fixed this issue by changing SIMs in slots, former secondary is now primary.

SG J510 apparently can not disconnect roaming and search for home network on SIM2 slot.

Real answer still appreciated.