Just to update everyone, it was a business classification issue. It took about 2 weeks to receive a secure link and instructions to upload my corrected W-2 and a "Financial Services US" form. Once I did that, payouts resumed in days. Really annoying,...

No it hasn't. Chat support said they've sent the info to the tax team. Mypayouts have stopped.

I'm having the same problem. My TIN and SS are both correct - nothing has changed from years prior - and Shopify is saying they'll end payouts tomorrow because they're not correct. I'm glad to know others are in the same boat.