ASA and BVOH adhesion
Can you tell by looking at the de-adhesion what isn't sticking?  

It may be that printing the ASA at higher temperature is melting the BVOH enough that it doesn't stick, being molten.  If so, then it may be possible to print the first layer of ASA at a cooler temperature, slower if necessary to still succeed at extrusion, with fans blowing.  Then, print the next layer of ASA at a higher temperature, also with fans flowing.

A test might be to print the BVOH, then a layer of ASA, and stop.  Let it cool and test the adhesion.  If it sticks under these conditions, then a better command of the temperature profile may offer a way forward.