Jennifer Hi 👋,
Thank you for additional info. It is a bit more clear.
I guess this is happening when you use your card for any purchase.
Did you enable dual pin on the card and added your saving account for the second pin?
If so and you enabled also the back up flag, if funds are not available on the first account, automatically the system checks if the second account has funds and use it.
You can just disable the flag to use the second account as back up. It will be used only if you use the second pin.
I hope 🤞 I managed to explain clearly 🤩
Regards
GG