Doesn't work with custom html tags

[tbunique]

Just installed the extension but apparently it doesn't work with custom html tags (or maybe the cause is elsewhere).

<mat-expansion-panel>
    <mat-expansion-panel-header>
        <mat-panel-title> Language </mat-panel-title>
    </mat-expansion-panel-header>

    <p>
       blablabla
    </p>

    <div>
        <h4>Current language</h4>
        <mat-form-field>
            <mat-select placeholder="Select a language">
                <mat-option
                    *ngFor="let language of languageList"
                    [value]="language"
                >
                    {{ language }}
                </mat-option>
            </mat-select>
        </mat-form-field>
    </div>
</mat-expansion-panel>

If I start with the h4 it correctly expans up to the div. If I expand once more, the selection disappears.
If I start with mat-form-field or mat-expansion-panel, it expands to the opening tag itself and then the selection disappears.