Yes, it appears all Sucuri.net has blacklisted all of the sites hosted on my main domain but they give no reason whatsoever for the blacklist. I ran a scan on every single site that I have hosted on that home domain. Their whole scan of my site comes up clean - other than for their blacklist.
How very interesting that they offer a "service" to remove the blacklist for $189.99!!!
Bluehost - a very good hosting service - has checked and also can see no reason for the blacklist.
So, I have written the Sucuri support service which may someday answer. Of course, their support service is closed. However some blacklist happy robot appears to be working overtime at their headquarters. I do not have a handy $189.99 to pay them to fix it. So maybe they will continue to blacklist my sites forever.
Can you say Sucuri.net SCAM??