Mat expansion panel is opened by default bug?
I finally found the problem.
It was about this : *ngIf="selectedIndex == 2". I replaced it by a boolean which is updated when I change tab (MatTabChangeEvent)
tabChanged( tabChangeEvent: MatTabChangeEvent ): void {
this.selectedIndex = tabChangeEvent.index;
if (this.selectedIndex == 2) {
this.displayBlock = true;
}
else {
this.displayBlock = false;
}
}