How did Apple’s engineers botch dual-sim functionality in iMessage? And how quickly will they fix it? This bug is two years old.

Former Android user here. I’ve used dual-sim before on non-Apple devices.

Here’s how it works on non-Apple devices:

1. Contact sends texts texts to my primary line. Messages are received.
2. Same contact sends texts to my secondary line. Messages are received, and stored in separate thread.

Here’s how it works on my iPhone 12:

1. Contact sends texts primary line. Messages are received.
2. Same contact sends a text to my secondary line. Absolutely nothing happens. No notification. No indication that any message has been received.
3. Same contact sends another message to my secondary line 45 minutes later, asking me what’s holding me up, since the meeting started 7 minutes ago. I don’t receive this message either.
4. Same contact calls me. My excuse of “sorry, I have an iPhone” falls on deaf ears. I enter the half-hour meeting 15 minutes late.

I am a software developer. I think I have the least patience of the *several* other users on this forum because I know how the development process works.

Testing. This is basic. BASIC. Entry-level common sense states that when you produce new features (like dual-sim functionality) you TEST those features - vigorously. I’m running on iOS 14.4 on an iPhone 12 Pro Max and yet I and several other people are hitting a wall that should have been torn down in a public beta for the iPhone XR.

And it’s not like this is a feature that one could understand and empathize with its being overlooked. What do you do with a SIM card? You text. You call. You use data. There are only three major features involved. And on every dual-sim iPhone, only two of those features work. And Apple has kept this bug around for TWO YEARS! Even after many forum posts have been made trying to solve this issue to no avail.

This deserves to be given special attention by the development team at Apple so it can be fixed in the next revision of iOS 14. No feature addition, bug fix or design change matters more than ensuring that the core features of your device function properly.

Every other dual-sim device on the market can separate threads for texts going to separate lines. This was done before Apple ever stepped into the dual-sim market. Apple had plenty of examples to work from yet somehow they still missed the mark.

My recommendations are to create separate threads for texts arriving to separate lines. And if the line which a thread was dedicated to no longer exists on that phone, the thread should be disabled, but still accessible. I say that because I already have 2 virtual SIM cards stored in addition to my physical SIM, and I switch between them as I run multiple businesses. I don’t want weird things happening to my texts just because I shut a line off temporarily. The safest thing to do is just disable the thread.

For now, I will have to switch to my objectively superior Google Pixel 3a to meet my dual-sim needs. Please fix this soon, because I really do like my iPhone. I spent a lot of money on it. It’s faster, smarter, and looks nicer than any phone I’ve ever had. But this glaringly obvious issue causes me not to trust this device, so I won’t use it for my business until I’ve seen evidence of this issue being addressed.

Have a good day; and as always: test your software BEFORE you release it - not after.