[BUG] (Scheduler) Event resize in vertical mode while there is a global scroll on page

[k6c8e4]

Description

When the page is scrolled vertically, resizing an event in vertical mode causes the event to jump by an offset equal to the scroll amount. This behavior is reproducible and consistent:

• No scroll → resize works as expected
• Page scrolled → resize jumps by scrollY pixels

Steps to Reproduce

Reproduced the issue here

1. Embed SchedulerPro in vertical mode inside a scrollable container or page.
2. Scroll the page down.
3. Attempt to resize an event.
4. Observe the event jumps by several hours, proportional to scroll offset.

Expected Behavior

Resizing should respect the actual pointer position relative to the scheduler, regardless of page scroll. The scheduler should internally normalize coordinates to its own container.

Screenshots / Logs

Screen recording

https://github.com/user-attachments/assets/52a5ee94-7cd8-4d10-9d7f-c64717194ad7

Environment

• OS: [Windows 11]
• Browser: [Chrome 142]
• Bryntum Version: [v6.3.3]

[taauntik]

Thanks @k6c8e4 for your detailed report. We've confirmed it as a bug!