Left scrolling issue for virtual slides due to thumbs integration

[AndrzejW2016]

Check that this is really a bug

• I confirm

Reproduction link

https://codesandbox.io/p/sandbox/error-github-swiper-thumbs-gallery-forked-3gcn85

Bug description

There is a problem when using Swiper v11.2.8 with virtual slides and thumbs. After moving forward through several slides - especially reaching the end - you cannot scroll back to previous slides using the navigation buttons or swipe gestures (the thumbs gallery loses sync with the large image gallery). Swiper seems to "lock up" at the end, not properly showing the active thumbnail.

The problem seems to be related to the combination of virtual mode and thumbs. While scrolling right works as expected, scrolling left stops working after reaching the last slide or quickly moving through multiple slides.

Expected Behavior

You should be able to scroll to previous slides even after reaching the end. Navigation should work in both directions at all times, large and small galleries should show the same active photo, active photo should be visible in small gallery.

Actual Behavior

After navigating to the last slide using the navigation arrows, the thumbnail gallery (mySwiper) stops responding correctly to the left navigation:

Clicking the "Previous" button initially scrolls left, then becomes confused, scrolls badly, galleries lose sync.

The main slider (mySwiper2) seems to work correctly.

This behavior does not occur only when reaching the end of the virtual slide list.

Swiper version

@11.2.8

Platform/Target and Browser Versions

Wersja 136.0.7103.92 (Oficjalna wersja) (64-bitowa)

Validations

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• Make sure this is a Swiper issue and not a framework-specific issue

Would you like to open a PR for this bug?

• I'm willing to open a PR