Have you tried creating H5P files in the LUMI app as described in https://docs.moodle.org/310/en/H5P#Creating_and_editing_H5P_content_elsewhere ?
If you can create a working H5P file in the LUMI app but not in your server's content bank it will likely mean you need a more powerful server (or you need to optimize your server's performance).
If you can create a working H5P file in the LUMI app but not in your server's content bank it will likely mean you need a more powerful server (or you need to optimize your server's performance).