Slow loading from the home LAN

Hi everyone,
I need your help, please.
Excuse me in advance: I am not a computer scientist and I have created myself a small server by myself, following a guide found on the internet.
On an old pc with cpu AMD Phenom with 4gb of ram, I had to install Ubuntu 18.04 LTS Server again, then I installed the latest version of Apache, mariadb, php7.2, and I installed Nextcloud Server 16.0.4, with memcache APCu .

The problem is this: when I make a large upload (more than 10GB, for example), from the network of my house (so with address 192.168. Etc.) directly from the browser, it really takes a long time, whereas before it was definitely more fast.
Oh I forgot: the LAN card is gigabite, as well as the router ports.
Where did I go wrong?
Thanks a lot to those who will answer me! :slight_smile: :relaxed:

This question cannot be answered in general. You have to check all parts which are involved in the data transfer, like the client CPU, memory, hard disk, network card, the server CPU, memory, hard disk, network card, the cabling, the router performance, Nextcloud cache setup (APCu, Opcache, Redis) etc., etc.

This might help you optimizing the server performance:

When was “before”? What has changed since then?

Excuse me if I answer you only now, but I’ve had a lot of work to do.
So with “before” I meant until a few days ago. I use Nextcloud with the hardware I described to you, from October 2018, and I’ve always done updates, both of Ubuntu and of NExtcloud. Unfortunately, just Ubuntu gave me problems, I can’t describe what, forgive me!, but I know it didn’t work well. Then I proceeded to a new installation of everything, and I found myself with the described problem.
j-ed asked me for more information on my hardware and the devices I use: compared to what I have already written, I can add that I have an Asus DSL-AC52U modem / router, and my server’s network card is NVIDIA MCP67 Ethernet at 66Mhz of clock.

I have tried, many times, to read the official documentation of Nextcloud, but it is too general and, at the same time, too specific for my knowledge.

However, by doing a deep formatting of the hard disk and re-installing everything (OS, Nextcloud etc.), I should have solved it.
I tried to load a 10 giga folder and it took about 40 minutes, while for a 2 giga file it took 3 minutes. Can you tell me about these loading times?
Thank you!