Description

It's possible to expand the timeline marker in Schedule Block and navigate to page 0, which breaks the timeline marker popup.

Steps to reproduce

1. Create new LP
2. Add Schedule Block
3. Add 6 Content Items to Schedule Block (in "now" timestamp), generating 6 Events
4. Publish LP
5. Select the violet marker on timeline
6. Click "Next" button
7. Click outside the popup to close it
8. Click the violet marker again
9. Click "Back" button

Expected result

Clicking back brings me to page 1/2 in popup

Actual result

Clicking back brings me to page 0/2 in popup. It's not possible to change the popup page without reloading the page. See attached screenshot.