// onResize() - BUG
if ((params.slidesPerView === 'auto' || params.slidesPerView > 1)
    && swiper.isEnd && !swiper.isBeginning
    && !swiper.params.centeredSlides && !isVirtualLoop) {
  swiper.slideTo(swiper.slides.length - 1, 0, false, true);
  //             ^^^^^^^^^^^^^^^^^^^^^^ DOM count (~4), not virtual count (~10)
}

The update() method already handles this correctly:

// update() - CORRECT
const slides = swiper.virtual && params.virtual.enabled ? swiper.virtual.slides : swiper.slides;
translated = swiper.slideTo(slides.length - 1, 0, false, true);

Fix

Apply the same virtual-aware pattern from update() to onResize():

+ const slides = isVirtual ? swiper.virtual.slides : swiper.slides;
- swiper.slideTo(swiper.slides.length - 1, 0, false, true);
+ swiper.slideTo(slides.length - 1, 0, false, true);

Note: isVirtual is already defined earlier in onResize():
const isVirtual = swiper.virtual && swiper.params.virtual.enabled;