[Software] Mouse cursor going opposite directions on vertical & horizontal axis

[JoshiFresa]

My Kubuntu kernel is 26.04 and I updated from 24.04 two weeks ago. The issue did not occur after the upgrade to 26.04 but later as I allowed some system updates that come daily. Although I'm not sure it's related to the update. Can't remember what update it was.

After I restarted the laptop, the mouse started to malfunction. I thought it was the mouse itself but I noticed that other people had the same issue as mine. When I move the cursor to the right it goes up. When I move up it goes to the left and so on. It can also stop cooperating and freeze except for the right mouse function that still works with contextual menus.

It's a dual mode mouse as written below it. I use it with a dungle if I remember the word correctly and it can be loaded via cable.

Not sure what else I could provide as data to help. Thanks in advance.

[claydoh]

Basic things to look at to get started:
Does it do this when it is wired?
Using a different USB port?
Do you have a different mouse to try?
it may sound silly, but have you unplugged the dongle and plugged it back in?

Make and model of mouse -- this information is probably key, as this is usually hardware-specific.

Does it happen in a different OS (Windows?) or a live Linux USB session?

Don't ignore the possibility of a hardware problem, even though it happened directly after an update --this has bitten me more than once

Make sure any reports you see about similar issues are not ancient. Mouse problems are generally pretty rare these days, though they were more common 20+ years ago., but stick to the past year or two.
If unsure, post links to them.

It helps if we can see what you see as much as possible.

[JoshiFresa]

Okay

Wired with dongle: it keeps being disoriented
Wired without dongle: it does not work
Different USB port for the dongle: yes I tried that and it makes no change
Plugging unplugging dongle: I also tried without success
Different mouse: Another mouse works YES
Does the mouse do the same on other platform/laptop/system: YES that's a killer test, wonderful!

First I thought, maybe the system reacted or had an issue only with tis mouse, but since this same issue is replicatable in Windows on another laptop, now there's no doubt left that my mouse fell into deep psychosis.

That simply solved the issue. Strange I haven't thought about the two last tests by myself. Being on a new system I become more easily clueless. Thanks Claydoh

[claydoh]

Strange I haven't thought about the two last tests by myself

Oh, no, this is completely normal. It happens to me soooo often. It IS too easy to blame Linux, and for good reasons, tbh. We forget that hardware and cables do fail. sometimes.

[Snowhog]

Occam's razor (or Ockham's razor) is a philosophical problem-solving principle recommending that when faced with competing hypotheses, one should select the solution with the fewest assumptions. Often phrased as "the simplest explanation is usually the best," it advises against unnecessary complexity, suggesting that "entities must not be multiplied beyond necessity".