解决方法

需在van-calendar上绑定@open="openCalendar"事件

 // 解决打开白屏，滑动后才可
    openCalendar() {
      this.$nextTick(() => {
        const calendarDom = document.querySelector('.van-calendar__body')
        if (calendarDom) {
          let back = calendarDom.scrollTop
          setTimeout(() => {
            back = calendarDom.scrollTop
            calendarDom.scrollTop = back - 2
          }, 10)
          setTimeout(() => {
            calendarDom.scrollTop = back
          }, 100)
        }
      })
    },