Game mode being enabled altering mouse movements

As best I can tell, you're having a problem with a Steam game. I'd start by asking Steam for help.

Also, it's very helpful if you use standard punctuation and break your post up into sentences. The solid, unpunctuated text is very hard to understand.

Just because other people have reported similar symptoms doesn't mean they have the same cause.

If removing the Arduino solves the issue, I'd say that's where the problem lies. Why do you need to use it?

Honestly, I think you'd have better luck on a board that focuses on using Arduino products. Or perhaps Apple's Developer Forums. This is primarily not a coding forum. And since the Arduino is the issue, you should be consulting with a group of people who are conversant with their use.

Unfortunately Apple doesn't disclose the lower level details of anything. At best the information available will be whatever is contained within Apple's developer documentation. Perhaps if you are part of the Apple developer program you may have an option to report the issue (or maybe not especially if you are an independent or small developer).

Even if you are able to report or file a bug report with Apple, it is doubtful Apple will even worry about it unless/until it shows up in other more main line areas.

FYI, it is extremely difficult to impossible to contact Apple in any meaningful way.

Perhaps you can find a more technical forum which may have people who specialize in such lower level development. You may even want to try in the Apple Developer Forums (it is hit or miss with the latter though).

Just adding to this --- I had game mode on for multiple games. For the last few months I've been having mouse/keyboard issues with World of Warcraft. Every 2-5 minutes, while full screen in the game, the mouse and keyboard would start causing erratic movements in the game. My character would start turning or running without me touching the mouse or keyboard.

I could not figure it out. I bought a new mouse and keyboard, I bought a new thunderbolt hub thinking it was that. Nothing worked.

I found a reddit post with someone having the same issue and they said turning off "game mode" solved their issue and BOOM, it solved it. Hundreds of dollars later and it was the buggy game mode. Which I will never, ever, turn on again. So people saying it's steam or your game are wrong.

Dav1d wrote:

I found a reddit post with someone having the same issue and they said turning off "game mode" solved their issue and BOOM, it solved it. Hundreds of dollars later and it was the buggy game mode. Which I will never, ever, turn on again. So people saying it's steam or your game are wrong.

I think you may have missed the part of the original post were the OP said that Game Mode was off.

Thanks for the edits! Now that I understand what you're asking, I know that I'm not the person to answer your question.

But, are you using a BT mouse? Or wired?

It sounds like you're introducing complications into the system. Does it work if you connected your wired mouse directly to the computer? If it does, it sounds like it's something with the Arduino.

What happens when you remove the Arduino from the equation? Does the mouse work if plugged directly into the Mac?