As I'm sure you have picked up, it seems that the seams are somehow related to the banding we are observing, right? (it is especially noticeable how the bottom left half the large hole has banding, coincidental to the white dots in the slicer.

But let's go a bit deeper. This is a single layer of the print. We see nothing weird in there, right?

Look what happens when we review the layer itself, and the order and direction that the nozzle takes to print it.

There, do you see it?

To help understand the issue, I can tell you that the nozzle works on both squares in a clock-wise direction AND the rear of the right square printed alright.

So, the #Anycubic #vyper is a bowden printer.
And more importantly, it's a cheap bowden printer. There is nothing wrong with it, but it means one "critical" component is not as good as it could be.
I am referring, of course, to the teflon bowden tube itself.

What would happen if the settings of the retraction were wrong?

Yep, there would be slight extrusion upon starting the layer.

Playing with the settings, I moved all the initial points away from the holes themselves, and this slicing is what gives out the nice red piece in the first image.

Now that I know it is retraction related, I can stop messing with the mechanics, and start dialing in the extrusion.

Also note this is why some people claim that using a different slicer, "solved the problem", it did not, it hid it behind, either in internal paths, or in less visually critical sides.