I just found another thread about this issue:
Channel registration — how can I check if the Google Form has been received?
It seems like @Liam-Shopify was able to help resolve the issue there and enable (or help expedite) order attribution for the app.
@Liam-Shopify, could you please look into my and @Jan_Ther’s cases? Both of us have been waiting for weeks (and in Jan’s case, months) without any updates, and our apps are still missing order attribution, which is blocking critical functionality.
Your help here would be greatly appreciated!