I have the latest iOS on an iPhone SE and macOS Mojave on a desktop computer with Airdrop and everything (not that latter matters).
However, SMS messages sent to my iPhone do not popup and now I am trying to send a message to an iPhone user from the computer and it is just loading.
Not popping up on the phone as failed to send either.
I've literally tried everything. Verified number, synced in iCloud, paired both with Bluetooth, USB, Wi-Fi, enabled and disabled all kinds of things on phone and computer settings. macOS is freshly installed so nothing wrong with the Mac.
Is this a known problem? I am a computer engineer so please keep that in mind when it comes to proposing the obvious like turn off the phone, iMessage, Bluetooth and so forth.