unknown error when trying to access livewire data

``php
        $updatedGroups = $this->mountedFormComponentActionData['groups'];
        ...
        $seatsPerGroup = collect($updatedGroups)
            ->map(fn($group) => $group['seats'])
            ->transform(function ($seatsGroups) {
                return collect($seatsGroups)
                    ->transform(function ($group) {
                        $bookingGroup
                            = BookingGroup::find($group['booking_group_id']);
                        return [
                            'course_id' => $bookingGroup->course_id,
                            'seats'     => $group['quantity']
                        ];
                    })->groupBy('course_id')
                    ->flatten(1);
            })->flatten(1)
            ->groupBy('course_id')
            ->transform(function ($courses) {
                return $courses->sum('seats');
            });
        $this->emit('updateGroups',[$seatsPerGroup]);