Hey, @Paul from Montreal. Welcome to the Photoshop Community. I'll need more info to help you figure this out.
Do you have any other programs or background services that may manage your input, such as a window manager? Has this started to happen since a recent update for Photoshop?
As a test, try using Photoshop (beta) from the Creative Cloud > Apps > Beta Apps section and check how it goes.
If that does not help, ensure there are no stale preferences in your Photoshop.
Go to the location of the preference folder mentioned below and rename it to back up. (https://adobe.ly/3u7u84j)
macOS: Hold down the Option key in the Finder when using the Go menu. The library will appear below the current user's home directory.
Library > Preferences > Adobe Photoshop [version] Settings
Rename the Adobe Photoshop folder by adding a .old at the end. (Adobe Photoshop 2025 > Rename > Adobe Photoshop 2025.old)
This will give a fresh start to Photoshop as a new installation.
Let me know if it helps. Thanks!
Sameer K
(Use '@mention' to tag me when you reply)