tl;dr: I can sign in just fine but can only send messages via Messages service every other day.
Hi, all. I have a perfectly functional Hackintosh with a Mac Pro 6,1 profile ... perfectly functional except for Messages. I can sign into Messages just fine and receive messages with no problem (though I suspect it's more that it's syncing the messages between my iPhone 7 and my Hack). Everything about my serial numbers and IDs is stable from reboot to reboot and the serial number itself isn't in Apple's database, and, as I said, I have no trouble at all signing in ever. I even tried switching to a different (verified-not-Apple-DB-present) serial number to no avail. iMessageDebug 2 shows all fields are populated with good-looking data that stays the same across reboots as well.
Here's the weird part: I can send messages just fine via Messages service (vs. SMS) every other day. Literally every other day it won't send all day, no matter how many times I go through the magic rituals outlined here and other places (including signing out of the Hack and all iOS devices, then back in, restarting, etc.). Then every other-other day it works perfectly fine to send via Messages service without my having to do anything at all.
When I first started noticing this pattern I thought it was coincidence so I started tracking it for the past 8 days. It's been consistent: a full day of working just fine, then a full day of not being able to send via Messages service. I don't know if it resets at a particular time as I'm 38 and need my beauty sleep. ;-) I have a sneaking suspicion it will start (or stop) working again after midnight PST. This leads me to wonder if it's Apple issuing a 24 hour ban. This is why I tried switching to another serial number.
Has anyone faced anything similar? Any ideas?