Not all iMessage messages going to iPhone...

I've searched for ideas how to correct this issue and checked all my settings. Right now there are three iPhone users whose messages don't go to my iPhone, but they go to my Apple Watch, iPad and iMac. When I message them from my iPhone, they get my messages, and those messages show up on my phone in blue bubbles. When I send from my other devices, everything shows up as it should.

I have my number and my iCloud account email address in each device. Both are able to receive messages, and new discussions are set up to send out from my phone number. On one of the other users, I have checked her settings, and they all appear to be in proper order.

I've reset my network settings. I've soft reset my phone. I have many other users whose messages are getting through, but the three people in question all report no other issues.

iPhone 6S

iOS 9.3.1