Honestly, I'm a bit surprised your setup works at all. I was under the impression that Core 0.15 exposed some packet deserialization issues that required an upgrade to Armory 0.96.3.

In any event, it would take me a long time to test this on a VM (I use -txindex and would have to wipe out some Core DBs if I went back pre-0.17). I'd prefer not to do that. Is there any reason why you're sticking to this particular setup?