[Vuejs]-Vuetify Datatable how to filter data without triggering API call each time

The problem is that pagination gets modified when you sort/filter items.
The watch handler receives val and oldval as parameter. You could check if the page has changed and only call this.getAllSystemsNewPage in that case.

watch: {
  pagination: {
      handler(newVal, oldVal) {
          if (newVal.page !== oldVal.page) {
            this.getAllSystemsNewPage(newVal.page); //Fetch new data and push into items
          }
      },
      deep: true
  }
}