@leocg it's super slow, full of clunkyness and bs, people are reporting slowdowns and other negative things about it, security on browser is bs also. Just search and see that the new Gx is highly disaproved right now.

@MaoMadosa Here's how to do it, i've been using the old version for a week and it works like a charm but i'll change to normal opera because gx is full of bs now.
The tutorial is made by the user burnout426, i was just lucky to find it.
I would:

Download the installer for 79 from https://ftp.opera.com/pub/opera_gx/79.0.4143.57/win/ to your downloads folder.

Uninstall Opera, but don't choose to delete your data when uninstalling.

Delete Opera's install folder if it remains.

Open up the Windows Task Scheduler and delete any Opera update tasks that remain.

Open a command prompt, type cd "path to your download folder", press enter, type Opera_GX_79.0.4143.57_Setup_x64.exe --launchopera=0 and press enter.

Click "options" in the installer, adjust things how you like, and install.

Then, before you start Opera, go into the "79.0.4143.57" folder in the install folder and delete opera_autoupdate.exe. Also delete the "assistant" folder in the install folder. Then, open up the Windows Task Scheduler again and delete any Opera update tasks you see.

Then, Opera updating will be totally crippled and it won't be able to update itself.

Besides that, if you have any security software like Kaspersky that tries to automatically update programs for you, make sure it's not set to update Opera.