Hello,
If you are setting strictWordStyles as true then most CSS styles are not applied (https://www.phpdocx.com/api-documentation/word-content/embed-html-Word-document-with-PHP):
strictWordStyles bool If true ignores almost all CSS styles and uses the styles set via the wordStyles option (see next).
You'd need to use width and height attributes instead of CSS styles. Or use HTML Extended and CSS Extended: https://www.phpdocx.com/documentation/introduction/html-extended-to-word-PHP, but this feature is available only in Premium licenses.
On https://www.phpdocx.com/htmlapi-documentation/html-standard/insert-image-Word-document-with-HTML you can read more information about working with img tags and the available styles and attributes.
Regards.