Multi-currency is changing the price in default country

HI there.
The default currency is set to the US. Prices are USD. However, when we enabled the multicurrency plugin, we found that 2 issues.
1. it listed a single price for all options (there is an upcharge for 2XL size clothing) so instead of the range it was a single price.
2. the single price that was listed was not the amount that we have set for the product. Where it should be between $16.95 – 18.95 depending on size – it made the entire range of sizes $19.95.
3. it does not show sales prices – nor the sales badge. Again, it just shows a flat $19.95

When we disable the plugin, all prices, including ranges & sales – return to normal. Obviously, we can’t have rogue pricing – so please address this issue.