Quasar QDialog component with updateable title?

Prerequisites: In Vue.js I have a DialogComponent consisting of qDialog and qCard where a <DIV> contains a variable title. This DIV is part of a header of the dialog within the component and title is exported such as: <DialogComponent :title="title" ref="myDialog">. Of course title is defined in data between properties in the DialogComponent.
To make it complicated: I defined DialogComponent in ComponentA (where are other dialogs as hidden inserted into vue.js app). In ComponentB of the same app I call function openDialogComponent(parameter) opening DialogComponent.

What I want do: I want to open DialogComponent which will have different title in header based on function parameter in openDialogComponent. Setting up new value for this.title based on parameter is no problem. The problem begins, when I call this.$refs.myDialog.title = this.title;. It doesn't load new value into DialogComponent, both, when I call this.$refs.myDialog.title = this.title; before or after this.$refs.myDialog.show();. I suppose title was inserted into DialogTitle, when was mounted into ComponentA.
I use: vuex 3.6.2, vue 2.6.11,quasar 1.19.4.

What event needs to be called on DialogComponent to update title with new value? Thank you.