Hello,
What version of phpdocx are you using?
We have run the the following code using phpdocx 13.5:
$docx = new CreateDocx();
$content1 = new WordFragment($docx);
$content1->addText('1.1', ['font' => 'Arial', 'fontSize' => 8, 'indent_left' => 10]);
$content2 = new WordFragment($docx);
$content2->addFormElement('select', ['selectOptions' => [' 0 ', ' 1 ', ' 2 ', ' 3 ']]);
$content = array();
$content[] = $content1;
$content[] = $content2;
$item = new WordFragment($docx);
$item->addText($content);
$docx->addText(array($item));
$docx->createDocx('output.docx');
and the output is correct. Both contents appear in the same line.
Also note that you can avoid generating an extra WordFragment:
$docx = new CreateDocx();
$content1 = new WordFragment($docx);
$content1->addText('1.1', ['font' => 'Arial', 'fontSize' => 8, 'indent_left' => 10]);
$content2 = new WordFragment($docx);
$content2->addFormElement('select', ['selectOptions' => [' 0 ', ' 1 ', ' 2 ', ' 3 ']]);
$docx->addText(array($content1, $content2));
$docx->createDocx('output.docx');
Please note that adding form and structured document tags as inline contents was added in phpdocx 13.5.
Regards.