conflict

We are using the ‘YITH WooCommerce Dynamic Pricing & Discounts’ plugin to give 10% discount on 3 or more items. (on https://lebonnet.com).
This is working fine for the default Currency (EUR) but as soon as you select a different currency the price is behaving very weird.

For example, a beanie is €70. In pound sterling we set the price to £60. The actual exchange rate from € to £ is 0.84.
There should be a 10% discount when buying 3+.
For EUR it’s displaying correctly; see screen-1.jpg.
For GBP however it messes up the original price and the sale price (see screen-2.jpg)
And the funny thing is that whenever i reload the page the price is actually lowered more (see screen-3.jpg)

I don’t know if you are familiar with the ‘YITH WooCommerce Dynamic Pricing & Discounts’ plugin but i hope you can help me out or at least point me in the right direction.

Thanks!
Oscar