I did test the PHP-scripts but i did only get errors. I don´t know much about php.
Everything is OK, only on the Front Page the header and main navigation should be sticky on the bottom and after scrolling should it be sticky on the top, but this is already OK.
This is my web-project:
https://www.simon-weber.de/wp2019/
I would get the behavior like Twenty Seventeen, without parallax.
Thank you!
Wolfgang