I don't know what you want me to do. Do you think Files app limits upload size on your server, but for nobody else? Your host has some hard-coded upload limit (this is normal, even if they don't say so) or you are using some proxy service like Cloudflare.
Do this:
Below is a link to a super simple PHP upload script for uploading a single file. Test it on your server, and you will find the same limitation.
https://gist.github.com/taterbase/2688850
Surely you understand that Files app cannot bypass limitations imposed by your server (or whatever is the cause). Files app can only use your PHP to upload, and if that's insufficient, then you need to deal with that.
I'm also a bit surprised that you have failed to provide me with 1. link to your Files app, 2. link to your optional upload app, 3 or FTP so I could do a simple test. This could have been forwarded in private, and this could have been resolved quickly. Instead, you want to continue posting in this forum in the belief that the issue is related to Files app and not your server/network.
ll5115 For the 6.43GB file, I use the upload function that comes with aapanel to upload the file. Their URL is https://www.aapanel.com/ and you can test the installation.
Does that look like PHP to you? No. Did you install this yourself? I think not, unless you have your own server. This is server-application that uses SSH that must be installed from SSH wget. It can't be installed on shared hosting, unless the host already has it installed for you (which is likely the case). Obviously, it can bypass any limitations imposed by PHP. This is not a web application ... it's a server application.
Sorry, but you really need to step up and give me access so I can show you it's your server. If not, then please stop posting here because you are just assuming incorrectly.
With no further replies, I assume you did the PHP test above and found out it's your own server.