I noticed an issue in mid December where a few messages in a row that were sent in a group MMS were never received on my phone. A few days ago, I had the same issue with an SMS message sent to me. There may have been other instances as well that I'm unaware of. In December, my default messaging app was QKSMS. In the instance a few days ago, my default SMS/MMS app was Signal.

I'm using an Asus Zenfone 6 on Wing's AT&T network (for those don't know, this essentially means Wing bought AT&T contracts in bulk and is reselling them individually).

I don't know of any issues with outgoing messages. The intermittent nature of this problem makes it difficult to troubleshoot. What steps can I take to ensure I don't lose any incoming MMS or SMS messages in the future?

  • Make sure in the mobile network config APN and MMSC are set correctly set as described here: help.wingalpha.com/hc/en-us/articles/…
    – Robert
    Feb 23, 2021 at 8:22
  • you registered Signal for SMS so you won't receive SMS to your SIM card any longer. instead the SMS is redirected to Signal server and sent to you as Signal Message via Internet connection. If you don't wanna lose SMS in future you need to unregister Signal for SMS receiving
    – alecxs
    Feb 23, 2021 at 10:16
  • @Robert I don't see any way to accomplish step 1 or 2. Listed options for Preferred network type are 2G/3G/4G, 2G/3G, 3G, and 2G and I can't choose a Network Operator anywhere that I can see. The default APN settings mostly matches what's on the page with the following exceptions: Name is ATT Phone Authentication type is Not set APN type includes fota APN protocol is IPv4/IPv6 Bearer is Unspecified If I set the bearer to LTE and save the APN disappears from the list. A new APN with bearer set to LTE also doesn't show up in the list. Does that shed any light on this?
    – ttshaw1
    Feb 23, 2021 at 17:01
  • @alecxs I had the same issue with QKSMS as my messaging app. Anyway, I think SMS and MMS are handled in Signal the same as they are in any other app and never go through Signal's servers. Where are you seeing that that's not the case?
    – ttshaw1
    Feb 23, 2021 at 17:03
  • register your phone number on signal. enable sms in signal settings. now remove the sim card and plug into any other cell phone for testing purposes - you won't receive sms on that sim card any longer. i don't know how other apps handle this. after this experience i don't use any messenger at all. for plain sms i use textra
    – alecxs
    Feb 23, 2021 at 17:46

1 Answer 1


In my case, the issue with the two non-stock messaging apps was the battery settings. Android was throttling the apps when they weren't in active use to save on battery. For whatever reason, incoming text messages would be directed to the apps but the apps would never wake up and the message would fall into a black hole. The stock messaging app was set to never be throttled in the Android battery settings. Changing Signal to also never be throttled seems to have resolved the problem. This is a known issue for Signal: https://support.signal.org/hc/en-us/articles/360027913252-Troubleshoot-receiving-messages

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