PDF download issue

There seems to be a conflict with caching plugins, I think this might relate to gzip compression.

PDF files are “corrupted” on download, but if you change the file extension to .pdf.gzip and open them with 7Zip the PDF file inside is viewable.

I specifically use Litespeed plugin as I have a Litespeed server, but I think the issue will be similar for others such as WP Rocket and Total Cache since they all force gzip compression.

For me commenting out these lines made everything play nice together

/src/php/core-addons/private-file/private-file-default-handlers.class.php 941,942 and 945