Um I may be a bit old for Reddit and therefore less optimistic/naive about the value of "open communication" and "talking it out" but life has taught me the hard way that not all communication is verbal. The fact that she is speaking to you as little as possible and interrupting you when you talk is communication--she's saying she doesn't want to talk to you.
Sometimes there aren't magical words you can say to make things better. Sometimes adults don't want to talk to each other, for so many reasons.
Sometimes there aren't answers to these situations. Even if you forced her to confront "the issue," there may not be one clear issue to confront, so you might just be forcing her to make something up, which will cause her to further resent you. I think the questions you need to ask yourself are instead: