Why is my Primary Sim automatically changing?

[mquin2112]

Anyone have any idea why my Primary Sim keeps changing automatically? I'm trying to keep my esim as primary and my work sim as the secondary. Setting for Data switch is turned off. It seems it automatically switches and makes my work Sim the Primary and I cannot figure out why. 

[Samsung_Moderator · Accepted solution]

Hey there! I would suggest reaching out to your carrier seeing as how SIM cards and service are carrier features! 

[guile014]

Worst answer possible. It's obviously a phone OS issue, I have the same problem and I have to check every now and then to make it didn't change it back.

[Members_VVXNBZu]

I am having the same issue now.

[mquin2112]

I believe I have solved the issue. I noticed with Dual sim, you also have Visual Voicemail. Inside the settings for Visual Voicemail, is the setting, allow data switching for voicemail. Since I've made sure it's off, my Data doesn't turn on automatically for my physical sim card, although I've yet to see how it affects receiving voicemail for that sim. Hopefully it's a solution for you.

[Xyverz]

This is the most promising solution I've seen yet, thank you! I noticed after I disabled it, that my phone automatically switched back to my (preferred) primary SIM.

[mquin2112]

Haven't had a single issue yet, with the exception of visual voicemail not working properly for the secondary sim. But oh well. People don't leave voicemails these days anyway.

[Members_VVXNBZu]

I am having this same issue. The OS keeps switching to my secondary line that doesn't have data and the phone stops working. I have to keep switching the primary SIM a few times a day now. This just started happening after the last update. No issues before that. Super annoying! Is there a fix yet?

[mquin2112]

I believe I have solved the issue. I noticed with Dual sim, you also have Visual Voicemail. Inside the settings for Visual Voicemail, is the setting, allow data switching for voicemail. Since I've made sure it's off, my Data doesn't turn on automatically for my physical sim card, although I've yet to see how it affects receiving voicemail for that sim. Hopefully it's a solution for you.

[arcnwlf]

I disagree, I have been having this problem too. It seems like this is an operating system problem, since everything I find about this issue implies that it is a user setting but the operating system keeps overriding it based on network availability. SIM services might be managed by the carrier but the phone itself is triggering the setting change.

I don't have any data on my 2nd SIM, so whenever this happens my phone stops working properly. I don't care if T-Mobile has 5G available and Verizon has no data in this location, I cannot use my T-Mobile SIM for anything but call/text so switching is not only useless but harmful for me.