I have just completed a fresh install using the online installer. I have the newest kernel and the LTS kernel and the LTS kernel causes this graphics issue (see below), the newest kernel is fine.
What could be going wrong?
My specs are:
Dell XPS 7590
Geforce GTX 1650 mobile
Intel UHD Graphics 630 built in graphics
16GB memory
Since the LTS kernel will soon be replaced with the new LTS kernel which is also 5.15, I probably wouldn’t spend a lot of time worrying about it.
Ah that’s good to know.
How can I find out when that happens? Will I be able to update from the OS or will I need to download a fresh ISO?
Just keep updating your system regularly.
No need to install afresh.
Keep an eye on your updates. You will see the version number of linux-lts change from 5.10.x to 5.15.x.
In addition to what others have said: you’ll know when it happens because LTS kernel won’t have this graphics glitch any more 
I used to have a screen like that and removed the intel driver to solve it.
Lol, thank you for giving me a small laugh on a slightly stressful morning 
How do I remove specific drivers?
Just remove the xf86-video-intel driver and reboot.