Free.

Use Cloudflare to point directly to your server. As a layer of security on top, ensure only certain emails or certain domains are able to get through to them.

I’ve done this about 1 year ago for my family and works flawlessly. Exposed Nextcloud, uptimekuma, immich, emby, etc. About 8 services.

Interesting.

Can you please test, upload from phone and upload from desktop?

If the phone has this problem, see if there’s the mobile, or desktop version of the web app creating the issue.

I am inclined to think that Android may strip some of the information? Not sure.