Weird Keyboard+Mouse behaviour

[Observerman]

Im using a "old" laptop. The Lenovo Legion Y720.
When plugging in my Microsoft Standard Optical-Mouse, there seems to be a chance, that at some point, either the mouse or my build-in keyboard starts to behave abnormal. Sometimes, the mouse starts constantly moving in any direction, still registering other inputs but with the constant movement nonetheless.
Sometimes, it gets almost stuck to some random point on the screen and i can only barely move away from it, but always get dragged back. And just now, the keyboard started to register "wrong" inputs like "K" opened up, adding new bookmark in firefox and many buttons not working anymore at all.
Whenever any of the above happens, unplugging the mouse doesn't fix anything. I always have to reboot the PC.
Im still pretty new to Linux and Kubuntu so please have mercy upon me.

While im at it. I can use the keyboard shortcut "Fn+F6" to deactivate my touchpad but activating it again isn't as easy as pressing the shortcut again.

[Snowhog]

Welcome to KFN.

Personally, I'd be thinking 'dirty' mouse and keyboard. Do you have another mouse you can swap out with? That would at least confirm/eliminate the current mouse as a contributor. Exactly how "old" is the laptop?

[Observerman]

the laptop is six years old. Ill try out another mouse and see if it happens again.
what exactly do you mean by "dirty" mouse? i guess you dont mean just some dirt on the mouse

[oshunluvr]

the laptop is six years old. Ill try out another mouse and see if it happens again.
what exactly do you mean by "dirty" mouse? i guess you dont mean just some dirt on the mouse

They get dirty if it's a roller ball mouse. Most are optical now-a-days. I suppose the optical portal could have some cruft on it.

I have had static problems with Logitech mice in the past. If it has removable batteries, putt them and click the buttons a bunch of times, then let it sit for a few minutes before putting them back in and trying again.

[Observerman]

Yeah, the problem occured with a second mouse aswell but i guess it has also something to do with Steam and multiple tabs?
Well, this time, i was playing "Slay the Spire", plugged in the other USB-Mouse and the moment i tabbed out of slay the spire, the cursor started moving a few centimeters from left to right all the time until i focused slay the spire again. The keyboard also registered wrong inputs again so i had to restart the laptop first before coming here again. Also, both USB-Mouses are clean as far as i can tell.
Oh, and i tried to reprodu
EDIT: while typing my post (with slay the spire all the time in the background active and the first mouse(windows standard optical) plugged in again) the keyboard started to malfunction again midpost without tabbing out of firefox or anything.
EDIT2: Often, for some reason the Ctrl-Button seems to be active even though i didnt press it once. I just realize it as soon as i try to scroll up or down a page using the mousewheel and everything starts to get bigger or smaller.

EDIT3:
Found the problem. It was my controller in my backpack which seemed to, for some reason, turn on and paired with steams controller plugin and its giro function made the mouse spin, weird button inputs and so on. So basically it was a nearby paired controller + steam.