Apple macOS High Sierra Bug Is Causing iMessage Delivery Issues For Some Users

There are forces in the universe that are working to prevent us mere mortals from communication with one another via text messaging, or so it seems. Earlier this week it was reported that Google is working on a fix for an issue that is preventing some Pixel handset owners from receiving text messages after upgrading to Android 8.0 Oreo, but Google is not the only one with issues. Apple is contending with a bug of its own that is causing some macOS High Sierra users to see a significant delay in arrive of iMessages.

There is a multi-page thread on Apple's support forum in which users are complaining of the issue. The original post was submitted several weeks ago, on September 26.
Macs
"Receiving messages on my Mac are now extremely delayed since installing High Sierra. They will show up on my iPhone, but without a notification so I can't see or hear it. Then several minutes later it will pop up on the Mac. I didn't have this issue with Sierra, and would rather not downgrade. Anybody else with this issue or suggestions on how to fix this?," the original poster stated.

It did not take long for others to chime in with similar complaints.

"I'm having the same issue. While signing into this forum, there was a delay in the two-factor alert arriving between my iPhone and MacBook Pro," another user wrote.

It is a particularly frustrating issue for affected users. In addition to delayed delivery of iMessages on Mac systems, users are not receiving notifications on their connected devices, such as iPhones and Apple Watches. In some cases, it is taking several hours for iMessages to arrive.

Some users have noted a bit of short-term success by disabling and re-enabling messages, or sending a message from their Mac system. However, these methods do not permanently solve the problem—the issue eventually return. The only real workarounds at the moment are to either disable receiving iMessages on an affected Mac system, or downgrading to macOS Sierra.