I am getting email notifications of comments again.
It has been almost a year.
I gave up several months ago being pulled away by life and believing a non-communicative web host had a mysterious setting somewhere they would not admit to.
The quarantine inspired me to take another look. I spent a week reading articles on the problem and getting frustrated implementing complicated solutions that did not work.
I finally decided to shut all 15 of my plugins off. Boom ! Email notifications worked again. I went through each of them one by one turning them on and off to find the culprit.
Fellow WordPress bloggers, do yourself a favor and avoid the plugin called “Replyable” by Postmatic.