[FO] Need help with ink/First finished project!

I used a water soluble pen I got in a beginners embroidery kit without testing it first and now I'm having issues with removing it. Any tips? I've tried sponging it off, soaking it, bleach, acetone and dish soap but nothing will get it off. I tried to test a different strip with some ink on it and water removed that without a problem, so I don't know why this line won't go away. First finished project :D not sure what I'm going to do with it now.