Checkout currency displays incorrectly (all currency symbols revert to MYR)

i’m experiencing an issue with my WooCommerce Multi-Currency setup.
On the cart page, conversion works correctly. Example:
MYR 68 → USD 18 ✅
On the checkout page, the amount remains correct but the currency symbol always reverts to MYR. Example:
Expected: USD 18
Actual: RM 18 ❌
This happens with all currencies (not only USD).