Laptop boots directly to windows 10 in Ubuntu (tried several things, see below) on Asus laptop

**Brief Description:**

After installing Ubuntu 20.04.1 on a separate partition, with Windows 10 installed on another one, I restart the pc after installation and it just boots to Windows 10.

**Setup:**

* EFI/GPT (not mbr/bios).
* Windows 10 / Ubuntu 20.04.1 dual boot (I tried 18 but with similar results).
* Laptop: VivoBook ASUS X571GT_F571GT (it has an Nvidia gpu, but I don't reach grub anyway to encounter the issues there common with Nvidia drivers (or lack thereof)).
* Let me know if there's any missing info to add here.

**Attempts:**

 * Disabled fast boot, secure boot, hibernation, fast startup
 * Gave top priority to Ubuntu boot loader in EFI/bios menu
 * Tried [this][1]
 * reinstalled grub in EFI mode following [this tutorial][2]
 * Resetting Windows 10 EFI entry following [this tutorial][3]
 * Reinstalling Ubuntu several times, formatting its partition and reinstalling again
 * using efibootmgr to remove Ubuntu's entry and also deleting the Ubuntu folder in EFI partition for a clean reinstallation
 * Tried Linux Mint and Ubuntu 18.04.5.
 * Updated EFI/bios firmware to latest version
 * Tried installing boot-repair on live usb, but it gave me no option for repair (recommended repair option)

Right now, I think the current state is that the Ubuntu installer has no effect, but I could be wrong of course.

**More details/history:**
This is a new laptop. The first time I installed Ubuntu I actually had a different result which is similar to [this][4], and also I got an error when I checked the box to install third party updates, so it wasn't a clean installation, keep in mind I formatted this partition multiple times after the first installation. After booting to Ubuntu from grub terminal and then restarting, I couldn't find grub anymore and it boots to windows. When I reinstalled Ubuntu again (or reinstalled grub from live usb don't remember which exactly), instead of getting the minimal grub terminal, it just freezes at Asus logo screen before grub. So it doesn't freeze at grub (due to gpu issues) but before that at the Asus logo, I had to repeat that because the gpu issue is the most common one.
And after a few other installations and attempts, it just boots directly to Windows 10, and I think the Ubuntu installation right now doesn't even work or have any effect.

  [1]: https://itsfoss.com/no-grub-windows-linux/
  [2]: https://askubuntu.com/a/1069886/1143073
  [3]: http://woshub.com/how-to-repair-uefi-bootloader-in-windows-8/
  [4]: https://www.geeksforgeeks.org/how-to-fix-minimal-bash-like-line-editing-is-supported-grub-error-in-linux/