What type of blur is this?

[rasaned]

I have a problem and I can't figure out exactly what it is. Could you please guide me?

My question:
What is the problem I posted in the pictures below? How can it be fixed? Is there a better group, forum, etc. where I can ask about this?

My lore and details:

One morning I woke up, and nothing had changed, but every game I played started to bother me excessively.
At first, I thought the problem was because the game I started playing had been updated, but no, this issue was present in every game I played.
I tried countless things over the weeks—formatting, clean installations of drivers, chipset drivers, changing BIOS settings beyond count—and finally replaced my monitor. I switched from a 60 Hz monitor to a 240 Hz XG2431 monitor (it was on sale).
But to no avail.

After visiting this site, I realised that my monitor wasn't really suitable for changing settings, and that's why I bought it.
By the way, my system is in good shape, and there's no bottleneck or anything like that. I just suddenly experienced this issue and couldn't figure it out at all.
I'm not someone who doesn't understand computers; I tried countless simple solutions and researched, but I couldn't find anything.

Is this tearing, stuttering, or something else I don't know the name of? What could it be, and why is it happening?
Months have passed, and my head is filled with information, but I still can't find an answer. If you could tell me if there's another place where I could ask this question, I'd be grateful.

-I did not use vsync in the images.-
-I took photos with my phone while drawing circles with the mouse.-