bug in compatibility with ultimate product add on from plugin republic

Hi guys,
I have a bug with the compatibility with ultimate product add on from plugin republic, I have deactivated all plugins except woo-commerce woo multi currency and ultimate product add on, I also deactivated all custom code from function php and the problem still happens.
the issue is after changing the currency and adding a product to the cart with an add on option that add extra cost to the price the price at the cart is not correct and the price keep decreasing without me touching anything, i made a short video of the issue please see link below. I appreciate any help you can provide to get it fix as website need to go live very soon and we would like to have the multi currency switcher option.

https://drive.google.com/file/d/1WQwD7ITyy74N3AFJhTtsPdEgEAhU0cFG/view?usp=sharing