Hello,
To enable fractional scaling in GNOME on Wayland run:
gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"
To enable fractional scaling on Xorg run:
gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']"
Mind you, this are still not tested by me, so i can’t guarantee the outcome.
In your case, you will need to run the second command, then reboot the system.