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