Thanks @tarekht for your very quick reply.
Unfortunately, I still have a thick border on the slider arrow after clicking on it as you can see here https://soiajewellery.com/wp-content/uploads/2021/02/Screenshot-from-2021-02-18-15-41-00.png
And also as testing allowed me to notice, I have a similar problem when I click within the “Product Item” bound: https://soiajewellery.com/wp-content/uploads/2021/02/Screenshot-from-2021-02-18-15-41-49.png
I hope the screenshots will help to target the issue.
Thanks again,
Best Regards