Consider the following minimal HTML page:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bad form</title>
</head>
<body>
<form>
<input name="unlabelled_input">
<select name="unlabelled_select">
</select>
</form>
</body>
</html>
Neither the input nor the select have a label of any kind. However, Lighthouse Accessibility only picks up the input:

If I run the Axe extension over the page directly, it picks up two different errors, "Form elements must have labels" and "Select element must have an accessible name":

but Lighthouse is only reporting the first of these. It should report both.