I think to say you did “everything wrong” is a bit of an overstatement. You can certainly fire dichro down, it just depends upon the look you are going for. However, given that dichro is a metallic coating, and that microwaves don’t like metal, I think you might meet with varying levels of success trying to fire it in a microwave kiln.(I’ve never used a uwave kiln, so no experience to share there0.
I agree that less processing time might help. Also, keep in mind that if you clear-cap the dichro, or if you fire face down, that some of the coating may migrate to the outsides edges and leave a slight “metal border” around the dichro piece which will look different than the rest of the dichro. In some instances, it can be a nice look, but it might also not be what you are going for. If you’re clear-capping, just cut the clear piece a bit larger.
Lastly, generally trying to fuse dichro face up to dichro face down will not work (metal to metal), unless you remove the edges of one piece so you are glass to dichro.
Jester’s Baubles Fused Glass Designs