RUTX11 Balancing problem with Starlink

Hello everyone.
I have an issue with Starlink when using WAN and the RUTX11 router. The modem and router are fully updated. I set up a 70/30 split with a SIM card in slot 1, but the SIM card still takes priority and handles most of the traffic, while Starlink keeps turning on and off. How can I properly configure the load balancing so that Starlink remains the primary connection and the SIM card is only used as backup?