[Vuejs]-UI is not updating after data change in vue

<span class="close-x" @click="aTags.splice(tagIndex, 1)">❌</span>

use @click="oDyData.atags.splice(tagIndex,1)

Because you are trying to reach aTags object which is undefined because you are getting this object from oDyData. O this might be the problem in your code. Also you have to use :key while using v-for property.