php-mode, poor highlighting

hey guys, I installed php-mode and when I open a php file I see that my php file is almost NOT highlighted. Variables, class names, strings, method calls are not really distinguished among each other. Is it how it's intended? If not, do you have any hints on how I can debug this issue? https://preview.redd.it/kwj3z6lz6dp81.png?width=730&format=png&auto=webp&s=82007868a9bd8557f9e841b89dfa320192e9b37d Thanks

ok, the very basic thing I could do is to reinstall the package. And it helped. It would be nice to know why it didn't work properly at the first place but I guess it's now going to be harder to find. Maybe something didn't compile properly...