nginx/1.26.1 as a reverse proxy strips the Content-Length field from response, no matter what I do

Hi everyone, first-time poster here. I am trying to run nextcloud AIO behind a nginx/1.26.1 reverse proxy. When I download a file from the nextcloud, in the answer there is no Content-Length field coming out of nginx, while it was there when nextcloud AIO sent it (I have sniffed the traffic with

Re: nginx/1.26.1 as a reverse proxy strips the Content-Length field from response, no matter what I do

I am awfully sorry for spamming this list. I just found out nextcloud starts sending the file several times, sometimes containing "Content-Length" and sometimes not. The one time it actually serves the full download, this is the header: ---