*Expected behavior*A value must be selected in the Select field.

*Actual behavior*A script error has occurred. (t.setNode is not a function)

Resources (screenshots, code snippets etc.)

Using only the option tag without the optgroup tag will work correctly.

const domain = $('#domain'); const optgroup = $('<optgroup label="Default"></optgroup>'); optgroup.append('<option value="localhost">localhost</option>); domain.append(optgroup);

const domainInstance = new mdb.Select(domain[0]); domainInstance.setValue('localhost');