S10 Not Receiving Calls on 4G, 15-Second Delay When Dialing

[Wyatt09]

Hey everyone,

I'm facing a frustrating issue with my Samsung Galaxy S10. When my network mode is set to 4G/3G/2G (auto connect):

I can’t receive incoming calls.

Outgoing calls take about 15 seconds of delay before they actually go through.

When I switch the network mode to 3G/2G (auto connect), everything works perfectly—calls connect instantly, and I can receive calls without any problem.

Here’s what I’ve tried so far:

1. Reset network settings and restarted the phone.

2. Confirmed that my phone software is up to date.

3. Tried my card on another phone and it worked and tried another card from another provider and worked fine, but when I tried a different card from the same provider on my phone the same problem accurd (also this card is old, like from 2014)

For context, I’ve been using the same SIM card since 2016, and I’m wondering if it could be an issue with the SIM being outdated. Could it also be a hardware problem with the phone’s modem or antenna?

Has anyone else experienced this issue? Any advice or suggestions would be appreciated!

[BandOfBrothers]

Hello @Wyatt09 and may I extend a Warm Welcome to the Samsung Community Forum 👍 

Sim cards can sometimes be at fault so having your network help with a sim swap might be beneficial. 

There is a diagnostic test tool found in your Samsung Members App and a Samsung Service Centre can assess your phone. 

If i can be of any further help please don't hesitate to ask  😎 

[Wyatt09]

Thank You for replying, i've run the diagnostic in the Samsung Members App, the sim test and all other tests runs perfectly all green, i don't know what's the problem, i've tried 3 different sim cards from the same service provider 2 old sim cards (mine 10 years old sim card and my friends 12 years old) and relatively new card from like 2017 - 2018 or so, the same problem with them all, all work normally only under 3G, when i tried a different sim card from another service provider it worked fine even under 4G, i called my service provider and they opened a technical ticket for me, and said they'll go back to me, i think i'll go and get a new sim card for my number if they didn't comeback to me by monday, if that doesn't work ill wait for them to fix it if something has changed in there network, if it didn't i'll have to change my number to the same service provider that worked fine, even i don't like it and like the current setup i have phone + service provider. thank you anyway, it's much appreciated.

[PlantPot]

Do you get the VoLTE symbol when the 4G mode is set ? If not then you may need to enable this feature. It seems odd that it cannot connect in this mode but can for 3G/2G. In UK O2 is the only 3G network still live so for others, without VoLTE calls can only be made ona 2G network which will take longer to setup but there is pretty good coverage everywhere. I assume your 4G data is not working either ?

If you look at the sim status from the settings menu what network mode does it say for voice ?