SIM 1 help on s23 ultra.

[JGBurke]

Hi everyone, anyone able to help?

My phone network is smarty UK and when I put the SIM into sim1 tray there is no signal, but when I go into Ireland for work it'll start roaming and work perfectly. It only started doing this about a month ago. SIM 2 has no problems at all. 

I want to use an esim so I would like sim1 to work the way it should. 

Thank you

[TechZilla]

Hi and welcome to the community, can I ask where you bought your phone from? Was it new? Have you spoken to Smarty? I am wondering if you reset the network settings if this would help?

I suspect that an esim should work as it won't be using a physical sim. It might help if Smarty can send their network settings to your phone over the air. Also worth running a diagnostic test from within the phone itself and see if anything shows up?

Also have a look inside sim manager and have a rummage Especially look at mobile networks.

[JGBurke]

It wasn't new, but has been working fine for 9 months. It is strange it works fine on SIM 2 but not SIM one which makes me think it has to be something to do with the phone itself. I will definitely try resetting the network settings and try diagnostics to see if that helps.
Thank you

[BandOfBrothers]

Hi @JGBurke  👋 

I did experience this issue too in that my Sim¹ slot preffered a particular network sim card over another in regards to network signal.

So for the interim I just used the secondary sim slot. 

However when I travelled sometime later in the UK I purchased a uk payg network sim from another network ,and just to see if the situation had changed I inserted the original sim back into the ¹st sim slot, and everything was fine, which in my particular situation led me to believe this was an anomaly that occurred, which then resolved itself. 

In addition to @TechZilla excellent suggestions 😀 i would also suggest > Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop or use a Tv's USB Port to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too { Possibly excluding the s²⁴ Series of phone's } 

And as a very last resort a back up phone and factory reset procedure. 

Do let us know how you get on. 

😎