Mouse Click Issues on MacOS

[limpid moss]

I'll try to distill and explain as best I can.

Computer:
2021 14-inch MacBook Pro with Apple M1 Max and 64 GB RAM.
macOS Tahoe Version 26.3.1 (a)

Context:

• Build 41 does not do this
• Build 42 does
• I had the same problem with Subnautica on this same laptop, so I suspect it's heavily OS-related but still haven't been able to track it down.

Symptom:
In Build 42, pressing the left mouse button down causes some kind of input lag for about 0.5-1 seconds (duration varies)

• ONLY the left mouse button does this
• There is no change in FPS or lag of rendering or game function (zombies keep coming, and they DO eat me)

Example 1

• Go into the options menu and hover over a checkbox. The background of the checkbox shows a highlight when you hover over it.
• If you move the mouse away from the checkbox, the highlight disappears immediately.
• This is normal/expected behavior.

For me:

• Hover over the checkbox

• Hold down the mouse button and IMMEDIATELY move the mouse away from the checkbox.

• The highlight does not disappear immediately, instead it lingers for the 0.5-1 second of lag.

• Hover over the checkbox

• Hold down the mouse button, WAIT for 1 second, and move the mouse away from the checkbox.

• The highlight disappears immediately.

Example 2

• If I repeat similar steps with an item in inventory I see
• The tooltip that shows when you hover over the item lingers in the same way
• If I press down the button and immediately move the mouse the inventory item still begins dragging once the delay passes, even though the mouse cursor is somewhere else at the time. Dragging works normally except for the distance between the dragged item and the mouse cursor.

Summary:

• When pressing down the left mouse button some kind of delay happens that affects only mouse input (keyboard is fine)
• The game DOES detect the location the mousedown event happens
• The game DOES NOT see mouse movement or ACT on the mouse event until after the delay

Things I have ruled out

• WIndowed/Borderless/Fullscreen
• Disabling Steam Overlay and Steam controller input
• Tried with trackpad and multiple external mouses (mice? ...mouses)
• Changed resolutions
• Tried "lock cursor to window"
• Removed my entire ~/Zomboid folder and let B42 recreate it all

Happy to try other things, I'd love to play B42.

Discovered something interesting. If I change the settings in macOS so that the right mouse button is the primary click, the left mouse button (now performing "right-click" functionality) works fine. So, it seems to be something at the OS level and related to the "primary mouse" click.

I'm a software engineer, but boring business applications. I don't know the guts of event handling in macOS or inside a game engine. I hope this information is helpful, and happy to get more info or do more testing if I can.

[heady oak]

There were some clicking issues reported a month ago, but they were not caused by the game, but by some sort of "Magnet App", do you have it? Or anything else running in the background when playing?

[limpid moss]

Yes! I was just typing this. I was doing more searching and discovered some folks have had issues with Magnet.

I didn't suspect it because it's for window placement and management, not a mouse pointer tool. Just confirmed if I quit Magnet everything is fine.