Transfer file through reverse proxy issue


I have a Nextcloud server behind a Fortiweb reverse proxy. The reverse proxy scans traffic with signatures. When a user transfers a file (pdf, jpg, …) via the web page or the Nextcloud client, the reserve proxy occasionally detects attacks.
This is due to the transfer format between the client and the server, the format must be base64. All this data flow is analyzed and the reverse proxy finds attack signatures in this data flow.
Is it possible to change transfer mode? Maybe in binary?

Thanks for your help

I don’t think changes in data format will eliminate false positive of the reverse proxy. It’s already hard job to detect malware inside “cold” files - trying to achieve this within data streams is even harder. I don’t think changing client protocol will change the fact your proxy detects non-existing threats…

is it possible to change the format?
Otherwise I risk bypassing type URLs /remote.php/webdav/, which is a shame