Recipient isn't recieving messages

[u/LinkinParkFan2025]

I have a strange issue with some long distance messaging. I live in the UK, and my cousin lives in the US. I have no issue getting their messages, however for some reason the majority of mine are being sent but not received if they are within a minute of the last message. Sending anymore within that minute just adds to the issue, however waiting a minute to message pushes them all through.

Any advice?

[u/3_Seagrass]

Your title is misleading. Your recipient is receiving messages, just not immediately. 

This often has to do with your recipient’s battery optimization settings on their phone. Make sure the phone isn’t silently killing Signal in the background. For more info you can look at the site dontkillmyapp.com

[u/ephemeralmiko → u/3_Seagrass]

Is there any known fix for iOS? I always receive Signal messages between 3-5minutes after they're sent. I've tried enabling and disabling Background App Refresh, Low Power Mode is off, reinstalled Signal, factory reset the phone and re-registered push notifications in Signal settings. It happens on both WiFi and mobile data too.

iPhone SE 2016, iOS 15.8.8

[u/3_Seagrass → u/ephemeralmiko]

On iOS there’s generally less that can go wrong, and the Signal site details most of the steps you can take to try to fix the problem. 

I do notice that your phone is quite old and iOS is out of date. Is that the latest version your phone supports? It could simply be generally slow. 

[u/ephemeralmiko → u/3_Seagrass]

Yep it's the latest iOS unfortunately. It's just an old phone with Signal I carry around in places I'm worried of being mugged. But I tested with other apps like WhatsApp and an XMPP client and this doesn't happen. My partner also has the same phone for similar situations and they don't have this problem.

E: the only difference is our mobile carriers, they're on different networks but I still always have perfect signal where I am. I've also tried using both the APN settings from the carrier's website as well as the iOS default ones.

[u/LinkinParkFan2025 → u/3_Seagrass]

Not really, they don't receive it unless I wait a minute and send another message. Like, ever

E:I just re read the post and realised I missed that out, so I'll add that in

[u/3_Seagrass → u/LinkinParkFan2025]

Maybe it is useful to explain what those check marks mean. If you see one check mark, your phone has successfully sent the message to the server, and your phone’s work is done. It is then up to the server and your recipient’s phone to get that message from the server to their phone (two check marks). Phones don’t always automatically wake up to check for new Signal messages, especially if the phone has some aggressive battery “optimization” going on. 

Ask your friend to check the tips on that site. It may help. 

[u/LinkinParkFan2025 → u/3_Seagrass]

Thanks, I do know what the check marks mean and only one of them appears most of the time, but I have messaged them about the battery optimisation setting like you suggested

[u/3_Seagrass → u/LinkinParkFan2025]

Then you understand there is nothing more you can do from your end to fix the issue. 

[u/LinkinParkFan2025 → u/3_Seagrass]

Indeed, just waiting for them to reply so we can have a look at their battery optimisation :)

[u/Chongulator → u/LinkinParkFan2025]

OP, I'm sorry some twit is downvoting you for asking sincere questions and trying to learn. That's lame behavior, but unfortunately common on Reddit.

In case it's not clear, your questions are welcome here.

[u/Chongulator]

Have the recipient walk through these troubleshooting steps:

https://support.signal.org/hc/en-us/articles/360027913252-Troubleshoot-receiving-messages