TL;DR
KuCoin API imports have major restrictions — it only supports the last 12 months of data and misses certain transaction types like Margin PnL, Earn (partly), Sub-Account Bot Trades, Crypto Lending, Spotlight, KuCoin Win, Fast Trades, and Borrowing. Full yearly data is only pulled when you save a new job or click Check Now, while the daily auto-import grabs only the last few days.
1) Transactions Not Imported via API
The following transaction types are currently not supported:
Margin PnL
Earn (partly)
Sub-Account Bot Trades
Crypto Lending
Spotlight
KuCoin Win
Fast Trades (not available via CSV either)
Borrowing
2) API Import Time Limits
KuCoin API only imports data from the last 12 months.
The data from the last year will be imported only when you either save a new job or click Check Now.
The automatic daily import fetches only the last few days of data.