Hi, I have ASA and sometimes see the same thing. I think it may depend what data ASA gets from the weather stations. One station may give you foggy conditions while the the next one gives you clear sky conditions. This may either reflect the real situation or a station may be faulty or deliver incomplete data. I don't think ASA does interpolate weather gradients between the stations. I am not sure if it helps to tick the global settings box?
Not only do I agree that interpolation between stations is not working quite right, the problem in my post actually refers to visibility transitions WITHIN the radius of a single weather station. Another example of what I'm talking about is when making a visual landing, it is not uncommon for the conditions to suddenly shift to IMC between the inner marker and the threshold.
I'm not having these extreme problems when using asv6.5: You can actually see what kind of weather you are descending into.