Best Currency Converter Price becomes much bigger after changing currency currency formatting

[winniezhou6300]

The first picture is what my store should look like. However, after I installed the Best Currency Converter, and changed currency formatting in Shop Admin —— settings —— general, the price in the storefront become much bigger shown in the second picture. 

By the way, after changing currency formatting, currency converter can work but the price in the storefront becomes weired. 

Can someone help me to solve this?

Thank you 🙂