how to solve Asynchronous Prop passing in Vue3

Hello friends, I'm using my custom made MultiStepForm in Vue2 for 4 years, But in Vue3 it's causing Issue. https://dev.to/yogeshgalav7/how-to-build-multi-step-form-in-vuejs-4n5b

   this.steps[stepIndex].step_valid=true;
   this.$refs.multiStepForm.submitStep();

Props are passing slowly or not changing at correct time. Inside MultiStepForm component with 'steps' as props, inside 'submitStep' Function step_valid is not coming as true. When used with watcher it shows the change, also it works on second run, hence most probably it's the timing issue but why it haven't occur in Vue2.