The exchange rejected the leverage change
The exchange didn’t accept a leverage change for one leg, and that leg keeps its previous leverage. Follow the exchange’s message, then set it again.
What it means
The exchange didn’t accept a leverage change for one leg, and that leg keeps its previous leverage. The exchange’s own message follows the colon. Results are shown per leg, so the other leg may have changed successfully.
What to do
Read the exchange’s message. It says why this change was refused.
Adjust accordingly and set the leverage again, for example to a value the exchange allows. Leverage must be a whole number of 1 or more.
For the leverage parameter, see Parameters.