Your suggestion didn't work for me (when I went to "Remove State Return" as you suggested, the only state in the list was my home state - WA wasn't listed there, so I couldn't remove it).
However I think I have found another solution - either that, or coincidentally, TT corrected the issue overnight!
Here's what I did: In Forms view, I opened the "Info Wks" and scrolled down to "Part VII-State Filing Information." The box titled, "Nonresident states" showed "WA." I was able to remove it there. I then saved the file, closed TurboTax, and re-opened - and to my joy, when I went to the section on filing my federal and state return, it only included my home state's return.
Hope everyone who's been frustrated by this glitch will be able to move forward now.
