currency changed overall

Hello

I have issue with your plugin

Iam using 3 currencies and using Currency by Payment method option

COD – EGP
Paypal – USD
another gateway – SAR

also using autodetect currency by country option

for example
a customer from egypt enter my website and currency appear EGP
at checkout page if he choose paypal, currency change to USD
for now that is good

but after he select paypal currency is changed in overall website to USD and not return to his currency EGP

i need currency change in checkout page only when choose certain payment gateway, not change for all site