[Vuejs]-Vuejs v-for execution difference with or withouth sub-components

It seems the problem is you have not declared a :key when using performance-test (a custom component) in a v-for. Try:

<performance-test v-for="o in objArr" v-if="log('base')" :mydata="o" :key="o.a">
</performance-test>

Note: o.a must be unique for each o!

Codesandbox working demo here.