SIM 2 can not receive SMS when on phone using SIM 1

[Geogre]

S21 Plus

Why can I not receive an SMS on my sim2 when I am on the phone using sim1?

It never works. I have a phone bundle on sim1 but use sim2 for personal banking etc..

So when I am on the phone using sim1, they are trying to send me an sms on sim2 as that is the number that is registered to them. Makes sense?

What setting is not right or is this not possible? On my Huawei and Motorola, it was a very fluid experience.

Help.

[Members_h67ehXc]

Try going to Settings/connections/SIM card manager. Check if both SIM cards are enabled, then further down to which services you wish to receive from each SIM card. 

Hope it helps 

[Geogre]

Hello. Thanks for the swift response. I tried that. I have been playing around in that menu and nothing. It is only allowing me to do call forwarding etc. Activate Dual SIM always. It is not affecting the SMSs though.  

I think this is a fail from Samsung. Not a big fan of the phone, so will just live with these quirks. There are many. 

Thank you though!

[Alfsdad]

I have two sim cards in my S21 and have no problems getting SMS and voice on either sim at anytime.

[RXM]

That's because you used to have a Dual SIM Full Active (DSFA) phone where both SIMs can receive incoming calls and texts and you now have a Dual SIM Dual Standby (DSDS) phone which puts the other SIM into standby mode when the other is in use.

The amount of DSFA phones out there is much smaller than DSDS which is the most common.

It's not a feature I'd ever need. In the example provided to help me understand, why would you need the person your talking to to send you a text? I'm sure there lots of utility in that type of Dual SIM but for my use case I can't think of any.

[andy765]

Solved (at least for Motorola)

I had the same problem when overseas :
- Bought local sim, placed in primary slot (SIM 1)
- Moved sim from back home to secondary slot (SIM 2)
- Activated data on local sim to get internet connection.
- SIM 2 SHOULD have been available still for SMS and phone calls.
BUT it wasn't.

So two-factor authentication was impossible because SMS
messages were not arriving on SIM 1.

My phone is Motorola, not Samsung.

But my solution was as follows :
- On both sims, under Settings/Network and Internet/tap on one SIM 1 / SIM 2 respectively.
For both SIMs, there are options for 'Call preference' and 'Messages preference'.
[ The default values for both had been SIM 2 (so causing SMS messages to be blocked). ]
- Change 'Call preference' and 'Messages preference' to 'Ask every time'.

Works perfectly.

Hope this helps

[sekito]

I have the same setup and issue.

sim2 for personal banking

But sim2 NEVER receives sims unless I'm doing a call on sim2 and then hang up just as they send an sms.

So if someone calls me from the bank, half the time it says the phone isn't connected.

If I use net bank and it sens a 2fa sms, it never arrives. I have to go in settings, disable sim1, then get the sms sent.

I can't believe Samsung Galaxy S21 phones cannot use dual sim.

[sekito]

Can you try pressing details on the esim sms. It arrives, but I see send time 5.10, receive time 5.35. Usually 5min or more wait. While other sim is 1min.