Can't download pdf version


We have Nextcloud 21.0.1 and the latest version of CODE installed behind a reverse proxy nginx with the “2. SSL terminates at the proxy:” file from Setting up Nginx reverse proxy - Collabora Office and Collabora Online .

It is working pretty well but we can’t download pdf version from “file/download/pdf” . We can download all other format (odt, doc, docx, rtf, epub) but pdf. If I check in the log file, I can found this kind of error every time I try to download a pdf :

[ websrv_poll ] ERR Download file [/opt/lool/child-roots/77Eog0oZ8r67Mntj/tmp/user/docs/iqimcpExcN6WxyC30X53WCFeceoXN24QBnZ6725LAQrEKzztqmXOtXGY8EXdc4W9/NAMEOFMYFILE.pdf] not found.| wsd/LOOLWSD.cpp:3243

Also, I was wondering if it is possible to save as pdf (or export as pdf) within nextcloud? I don’t need to download in my computer…