Some options don’t work properly

Hi there,

I have a fresh install with a default theme (TwentyTwenty), but the (horizontal) timeline only ever shows three items (on the frontend) – the setting for “VigibleItems:” (?) only works in the backend.

Also, once I changed the “Start Index:” I cannot set it back to start with the first item, because it obviously counts from 0 (zero) which is not an option.
Basically, as soon as I change “Start Index:” the count is off by one.

And a question: if I’d want to show 10 items at once (on desktops), how, if at all, is this handled on narrower viewports (before it switches to vertical)?

Please, have a look. Thank you.

Best regards.