Hello,
phpdocx is fully tested with PHP 5.2 to PHP 7.1 (and beta PHP 7.2) on Linux (Debian, Ubuntu, RedHat, CentOS and other distros), Windows and macOS. There's no know problem when adding tables using the embedHTML method. Please post the most simple HTML that illustrates your issue and the version of PHP you are using and we'll check it.
About phpdocx 7.5, the changes from phpdocx 6.5 about importing HTML are improvements when using colspans and rowspans, but images didn't include any change. We have tested it with phpdocx 6.5 and phpdocx 7.5 and the same code works perfectly; when adding images we recommend setting the downloadImages as true to insert them in the DOCX, maybe you are not using that option?
Regards.