After Upgrade To 4.12 - Shipping Rate Is Not Working With "rate Areas" [Error Price Rate Was Not Set.]


After upgrade to 4.12 I am getting the following issue:

I have created a Rate Area includes 7 countries (one zoon) and I created a shipping method for this Rate Area.

The issue is that when I select this Rate Area and add shipping rate to it, the calculation is not working and I get "Error Price rate was not set." message.

This issue disappear when I add countries separately ..

Any help please?