Creating Bitmap drawings in Photoshop, then vectorizing them in illustrator to import to Toon Boom Harmony 17 - help!

I’m trying to take assets I have created in photoshop, vectorize them and then import them into Toon Boom. I’ve been using image trace in Illustrator to vectorize the assets but I am having trouble importing them into Toon Boom Harmony correctly. I try to open the .ai file into the Toon Boom library, the file loads empty, nothing shows up on the stage. I export the assets as images from .ai to import on the timeline in Toon Boom, they are pixelated and I cannot scale them up. I don’t know what I’m doing wrong.