Notebook Wireless and Networking

Hi everyone,
This problem is driving me crazy. I have a HP Pavilion Gaming Laptop 15-CX0003NL that mounts a Realtek rtl8822be card to connect to the Internet via Wi-Fi.. but something isn't working properly.
Basically, if I turn on Wi-Fi on my Laptop, and I immediately  perform a speedtest, the Download statistic reaches 250Mbps, that's exactly what my router offers and what other devices are able to get, at the same place where my laptop is at.

When it performs the test for Upload, the wireless card starts to decrease its performance, showing 40Mbps as result. All following speedtests give as result 40/50Mbps for both DL/UL. Only the first time it's fine.
What I mean is that the card gives the maximum performance when it starts to work, but after 1 minute it stops working properly.

Before writing this message, I tried to find a solution.
1. I've literally tried to manually install any possible driver for this network card (64bit), outdated and the most updated ones, but I got the same disappointing results. I've also tried HP Support Assistant to automatically update its driver. Nothing.
2. I've tried to disable power saving, for the Laptop and for the network card (so the laptop was unable to apply power saving settings for it), but nothing.
3. I checked if other programs installed on my Laptop were using the Internet Connection. There wasn't any other program.
4. I tried to update the BIOS, because some users got similar issues with the same network card and updating the BIOS worked for them. Unfortunately this isn't my case.
5. I tried to disable Bluetooth, because some users got it working after this. Didn't work for me.
6. I've disabled auto config. I tried to disable it manually or using the command netsh wlan set autoconfig enabled=no interface="name of your wireless network here" , but this didn't fix the issue.
7. I tried to change the radio channel width, from "Auto" to "20MHz Only". Same.

After following all these operations, my Wi-Fi connection keeps dropping so much, and as I said it's not an issue of my Internet Connection or router, seen that any other device here works as intended.

This really seems a common issue when using this network card. Some users got it properly working following one or more steps that I mentioned above, others continue to experience issues, included me, and this issue deserves to have more visibility!

Please! Can anyone support me? Anything else I can try? I don't know what else I might do to fix it.. Thanks.