изменить на
override fun convert(helper: BaseViewHolder, item: Tweet) {
val medias = item.medium.split(",")
if (!item.video) {
helper.getView<View>(R.id.vp).show()
helper.getView<View>(R.id.insdotview).show()
helper.getView<View>(R.id.videoview).hide()
val ad = TweetPhotoAdapter()
val a = medias.toMutableList()
ad.setNewData(a)
val vp2= helper.getView<ViewPager2>(R.id.vp)
vp2.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
LogUtils.w(position) // this line
super.onPageSelected(position)
}
})