Override External Monitor Geometry

Arrange the orientation the same as the displays are physically setup. Starting from the Mac display side/drag each additional display to where it correctly intersects with the Mac or last display.

To help with fine tune the intersection of each display to the next. Open a small window on the Mac's display and drag it half way across to the next display and align those two displays. Then do the same to align any additional displays.

For more detailed help, I'm going to need to see a physical photo of your multiple display setup and a screenshot of the Arrange Displays panel.

Still looks to me like a PPI issue.

I don't believe that the Mac knows the physical dimensions of the external screens. It knows the LCD panel resolutions of its internal screen and of the attached screens. It also knows the Displays Settings "resolutions" for each of these screens. When you stretch windows across multiple screens, there is very likely an assumption that in terms of sizing and positioning, a "Displays Settings" pixel is a "Displays Settings" pixel is a "Displays Settings" pixel. Obviously that works better with identical PPIs than with ones that are very different.

If the Mac is running the internal display in one of the most likely Retina scaling modes, the physical text & object sizes on that display would be smaller than those on the HP displays. There might be one crossover point – with each HP display – where things exactly lline up. But for the HP display that is "below" the Mac, things to the left and right of that crossover point are going to appear to be stretched out to the sides.

If you are referring to resolution..?

see > Change your Mac display’s resolution - Apple Support

If you need to move the arrangement (physical location) of displays..?

Click Arrange... in display settings, click hold and drag the displays to the desired orientation.

see Arrange at > Displays settings on Mac - Apple Support

Or if you need to rotate the image on the portrait display..?

Select that display in display settings and change the Rotation to 90 or 270 degrees.

see Rotate at > Displays settings on Mac - Apple Support

The HP EliteDisplay 241i is a 24" monitor with a resolution of 1920x1200 pixels, which translates to about 94.33 PPI.

An Intel-based 16" MacBook Pro has a screen with approximately 228 PPI. I believe that all of the 16" Apple Silicon MacBook Pros have screens with approximately 254 PPI. You'd probably be running the built-in screen in a Retina scaling mode (to use some of the PPI for more detail, rather than for cramming a bunch of too-tiny-to-read text onto the screen) – but even if you adjust for that, I would guess that text and object sizes are going to be different on the MBP's screen than on the HP displays.

So when you cross over between the MBP screen and one of the HP screens, there is probably only going to be one place where the crossing is exact – with no "jumps". The further away from that center point that you do the cross-over, the more the pointer is going to jump as it moves from one display to another.

At least, that's my understanding.

The Classic example is to connect a standard definition TV set of HUGE size, say 60 inches diagonal. It has only 1920 pixels across by 1080 pixels tall. Each pixel is just Really BIG.

At around four feet wide, that TV set has a far LOWER resolution than a Mac Built-in display, and has NO HOPE of automatically lining up, pixel-for-pixel, with the Mac Built-in display.

The Mac works only with screen resolutions. It does not know or care if you are using displays with Wildly different pixels-per-inch. It also does not provide any tools for lining such wildly different resolution displays up. To line up wildly different displays, you must you manually manipulate the resolutions to line it up yourself.

dangermen wrote:

How the Mac actually perceives the geometries is not right.

How does it perceive them?

What do you mean by "geometries"? Are you referring to resolution?