BackToTop - There's NO smooth transition in Safari

[turolopezsanabria]

Describe the bug
There's NO smooth transition in Safari, the scroll "jumps" directly to the top

Steps to reproduce

1. Go to back to top using Safari or Chrome in iOS
2. Scroll down
3. Click to scroll up
4. see error

Expected behaviour
The smooth transition should also work in Safari

smooth.doesnt.work.mov