Can we test:
sudo nano /etc/default/grub
Change:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"
Tap ctrl+x to exit the document editor, then the y key to say Yes to save, then the enter key to save the current configuration.
The terminal will revert to normal.
Now run
sudo update-grub
Reboot and test...
If that helps the issue, it at least gives us some idea of what is going on.
You will see higher power consumption and less acceleration in this mode.