Hello Enigmastu30,
welcome to the Apple (user-to-user) Community.
Re: "so I use the zoom window for a specific part of my tablet, never had any issues in the past till the recent iOS update. Now when I switch my zoom box back on it always has moved to the right slightly, which means I need to keep trying to move it back to its fixed position."
Sometimes things change in order to facilitate new features
You may want to check the settings, (especially for a "pinned" Zoom window), are as you want them to be:
Apple Support's article for iOS 18: Zoom in on the iPad screen - Apple Support
Eg: says:
"Use Zoom
- Double-tap the screen with three fingers or use Accessibility Shortcut to turn on Zoom.
- To see more of the screen, do any of the following:
- Adjust the magnification:
- Double-tap the screen with three fingers (without lifting your fingers after the second tap), then drag up or down. Or triple-tap with three fingers, then drag the Zoom Level slider.
- Move the Zoom lens: (Window Zoom) Drag the handle at the bottom of the Zoom lens.
- Pan to another area: (Full Screen Zoom) Drag the screen with three fingers.
___________________________________
To adjust the settings with the Zoom menu, triple-tap with three fingers, then adjust any of the following:
- Choose Region: Choose Pinned Zoom, Full Screen Zoom, or Window Zoom.
- Resize Lens: (Window Zoom) Tap Resize Lens, then drag any of the round handles that appear.
- Choose Filter: Choose Inverted, Grayscale, Grayscale Inverted, or Low Light.
- Show Controller: Show the Zoom Controller.
______________
To use the Zoom Controller, do any of the following:
- Show the Zoom menu: Tap the controller.
- Zoom in or out: Double-tap the controller.
- Pan: When zoomed in, drag the controller.
While using Zoom with an Apple external keyboard, the Zoom region follows the insertion point, keeping it in the center of the screen. See iPad keyboards. "
All the best :-)