Postgres lowercases every identifier you don't put in double quotes. userId becomes userid, which doesn't exist, because the column was created with quotes as "userId".
select * from orders where "userId" = '...';The app works because supabase-js quotes names for you.
Long term I'd rename to snake_case (user_id, created_at), which is the Postgres convention and saves you quotes forever. But that touches every query in the app, so only do it with a plan (and ask Lovable to update all references in the same step), not on a Friday.