ai-bookkeeper splits a Shopify Payments payout into sales, refunds and fees. Its category table was written from memory, so anything it did not know became "other income".
Shopify's Admin API reference lists 116 transaction types. 97 of them were falling through to other income, including shipping labels, referral fees, billing debits, customs duties, loan remittances and transfers between merchants. A merchant who bought shipping labels through Shopify would have seen a negative line in income instead of a cost.
The reader now books them as fees, refunds, disputes, tax, sales or a clearing account (loans and transfers move money, they are not income). 20 types stay as other income because their names say nothing about what they are, such as anomaly credits and Shopify Collective entries. The reference gives names only, so every mapping is a reading of the name, and no real Shopify payout export has been tried yet.