iMessage slow to send messages on iPhone 4S since updating to iOS 9.0

[damian]

Ever since I updated my iPhone 4S to iOS 9.0, messages have been delayed by at least 10 seconds, when I send them via iMessage.

To be clear, the delay is in the sending by my phone, not the receiving by the recipient. I see a blue progress bar move partway across the screen, then stall near the right edge for 10 seconds or more, when sending the message. The recipient receives the message at about the same time as the iPhone shows it as delivered.

There's no delay when I receive iMessages, or send SMSs.

There's also no delay when I send iMessages from my Mac.

There's also no delay when my girlfriend sends me iMessages, using an iPhone 5C running iOS 9.0, on the same Wi-Fi network.

I tried the following strategies, none of which helped:

• turning off wi-fi
• rebooting the phone
• resetting network settings

Is anyone else experiencing this problem?

Has anyone found a solution?

Can anyone suggest a solution?

 

[damian]

I reported this at http://bugreport.apple.com on September 19.

An Apple engineer responded on September 21, asking me to send diagnostic logs, which I did.

I suggest reporting it as well, if you also are having this problem, and you want to help get it fixed ASAP.

If you're not a developer, you can make a report at http://www.apple.com/feedback/

I suggest referencing my report (report #22772424), while doing so, so that the engineers can link them together easily.

Here's the full text of my report, in case it's helpful:

Summary:
Ever since I updated my iPhone 4S to iOS 9.0, messages have been delayed by at least 10 seconds, when I send them via iMessage.

To be clear, the delay is in the sending by my phone, not the receiving by the recipient. I see a blue progress bar move partway across the screen, then stall near the right edge for 10 seconds or more, when sending the message. The recipient receives the message at about the same time as the iPhone shows it as delivered.

There's no delay when I receive iMessages, or send SMSs.

There's also no delay when I send iMessages from my Mac.

There's also no delay when my girlfriend sends me iMessages, using an iPhone 5C running iOS 9.0, on the same Wi-Fi network.

I tried the following strategies, none of which helped:

• turning off wi-fi
• rebooting the phone
• resetting network settings

Steps to Reproduce:
Send an iMessage.

Expected Results:
The message sends immediately.

Actual Results:
The message is delayed by at least 10 seconds

Version:
iOS 9.0 (13A344)

Configuration:
iPhone 4S using Verizon 3G or Wi-Fi​