Laptop Screen Laggyness on Ubuntu 22.04, 23.10 and 24.04 beta, but image is fine on external display

Hi, recently I bought a Dell Latitude 7430, and decided to use it with Linux. However, the screen has stuttering, lagging, tearing, cursor is slow, and brightness flickers sometimes.

I've tried the following distros and versions:
-Ubuntu 22.04.3
-Ubuntu 23.10
-Pop!_OS 22.04
-Pop!_OS 22.04
-Xubuntu 23.10
-Garuda 231029
-EndeavourOS Galileo 11 2023
-Fedora 39
-Clear Linux 40580
-Arch Linux 2023
-Nobara 39

So far, I haven't had any results. The only way to install the above versions was to initialize installer in safe graphics mode, but CPU consumption was very high. Ubuntu 20.04.06 worked out of the box without graphics issues, but It couldn't find the network adapter. I also tried using X11, Wayland, switching resolutions, and changing the kernel to OEM without success.

A friend suggested connecting the computer to an external monitor, and everything was perfectly fine on the external monitor, but on the laptop screen the experience was awful.

Thesee are the computer specs:
-BIOS and firmware are up to date
-SSD is not in RAID
-Bitlocker and Windows certificates are deactivated
-Also tried deactivating Turbo Boost, deactivating Secure Boot, and deactivating Hyperthreading
-CPU: 12th gen Intel Core i5 1235u x12
-RAM: 16GB
-GPU: Intel Graphics Alder Lake-UP3 GT2 Iris Xe
-Firmware: 1.20.0
-Disk: 512GB

I asked on linux answers.org, and mrmazda suggested to try with fedora pre 40 and ubuntu 24.04, which uses newer kernel versions. The results where the following: fedora 40 pre: no screen tearing, but cursor is super slow, as if it has problems rendering the frame.
ubuntu 24.04 beta: a little bit of tearing on the buttons when they change state, rendering problems when I change window and cursor is super slow.

I made the election to buy this laptop beacuase it was certified by canonical: https://ubuntu.com/certified/202201-29871
20.04 LTS runs great without screen issues, but it won´t detect network adapter.

I hope you can help me, thanks in andvance for all your help.