Can't download backups

[swift2512]

Maybe someone will point me in the right direction. I have a problem that I can't figure out.
When APP_URL is set to http://snipeit.mydomain.here, I can upload/download ZIP files to/from different Snipe-IT views, but not from/to 'Admin settings > Backups'. If I rename backup.ZIP to backup.PDF - I am able to download or delete this PDF file from 'backups' view. For some odd reason only PDF works.

And as soon as I fall back to local IP address and leave everything else unchainged - ZIP download/upload works as expected in 'Admin settings > Backups'.

What am I missing? Nothing in apache2 error log. But in access log things look differently: it's HTTP/1.1" 200 vs. HTTP/1.1" 302

When Snipe-IT is on IP:
10.x.x.x - - [23/Mar/2026:10:59:59 +0200] "GET /admin/backups/download/backup.zip HTTP/1.1" 200 241847 "http://10.x.x.x/admin/backups" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Edg/146.0.0.0"

When I switch to subdomain:
10.x.x.x - - [23/Mar/2026:10:28:22 +0200] "GET /admin/backups/download/backup.zip HTTP/1.1" 302 1669 "http://snipeit.mydomain.here/admin/backups" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.>
10.x.x.x - - [23/Mar/2026:10:28:22 +0200] "GET /login HTTP/1.1" 302 1639 "http://snipeit.mydomain.here/admin/backups" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Edg/146.0.0.0"
Still on subdomain, PDF file downloaded from backups:
10.x.x.x - - [23/Mar/2026:13:01:12 +0200] "GET /admin/backups/download/test.pdf HTTP/1.1" 200 245030613 "http://snipeit.mydomain.here>

[swift2512]

It was network related.