Galaxy S23 Ultra - Issue using 4g and 5g network after ONE UI update 6.1

[Ritz2425]

I am having the problem using 4g and 5g network on my recently purchased S23 ultra. I updated my device to the latest One UI (version 6.1) yesterday (8th September 2024) and post that I am not able to connect to 4g or 5g network. I am unable to do any transaction when I go outside. The place I use the device is the same place I have been staying for 10 long years. It bought it recently (August 1st week 2024). Issue started yesterday when I went outside and tried to do a UPI payment in Bangalore India. The network provider is the same and I have enough data left on my number. Please resolve this ASAP since its very difficult to use for anything outside my house. 
Device details: Galaxy S23 Ultra.

[Piper123]

Hey there and welcome to the Samsung UK Community Forum

As you are based in India, you would be best reaching out to your local forum for guidance.

[BandOfBrothers]

Hello @Ritz2425 

First try a Hard reboot. 

https://www.samsung.com/uk/support/mobile-devices/my-galaxy-smartphone-has-frozen-how-do-i-restart-i... 

As a process of elimination can you try your sim card in another phone and then see what happens. 

If you can also try another Sim card in your phone. 

You can reset your Network Connection via Settings > General Management > Reset > Reset  Network Connections  > Turn the phone off and On. 

A good troubleshooting step is > 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 }

There is a diagnostic tool found in your Samsung Members App. 

A Samsung Service Centre can assess your phone. 

I wish you all the best with this. 

[Members_gZZvYjm]

Same problem with S23 ultra. Phone is useless.

[Piper123]

Have you followed the suggestions above?

I have S24 Ultra and S24 Ultra and not having any issues with either.

Have you tried to Reset MOBILE Network Settings on your device?

[SFRG]

I'm having issues with the network, my lyca network drops out all the time. I put on aeroplane mode and restart all the time. Please help if anyone has a solution. Since the update I'm having an issue.

[simonhardcastle]

I'm having the same problem. From the UK; roaming in France is useless. However, seems fine in Switzerland. Have tried everything recommended, also tried manually selecting a provider, nothing works. Thinking my next phone won't be Samsung (1st time in over a decade)

[Calvin13]

i have the same issue before. The phone won't switch from Wifi to 4G/5G when I'm out of wifi connection. I need to set to airplane mode on and off.

I have tried to do this: go to Settings, Connections, Mobile network, Access point Names. I Delete wherever not my existing APN and left with only 1 APN. It works for me.

[AndrewL]

@Calvin13: While I understand that you have found a workaround for your issue, please trying heading to Settings > Connections > Wi-Fi > Tap the 3 dots in the top right > Intelligent Wi-Fi > Switch to mobile data > On > Turn Wi-Fi on/off automatically > On. 

With these features activated, you should find that your phone automatically switches to Mobile data when you are out of range of your Wi-Fi router. 

[simonhardcastle]

I looked at these settings. The Switch To Mobile Data option is greyed out with the message 'Not available when data roaming'.