Synching iMessage across devices.
For years I have iMessage has worked across all of my devices (iPhone, Apple Watch, iPad and MacBook). Over the last several weeks it has been spotty to non-functional. It will synch then it will not. I am signed into iCloud on all of the devices. Iphone is set up to forward to both the Mac and iPad. On all devices it recognizes the two email accounts that I use for receive and send and on the iPhone it also has my phone number. I've tried signing out and signing back but that has not produced any improvement. I'm considering buying an iMac but now am a bit reluctant until this is resolved. Anything that I am missing or need to do?
iPhone 6, iOS 12