私も、同じ現象が起こりましたが、下記のURLで問題解決しました。
https://helpx.adobe.com/photoshop/kb/photoshop-and-macosmojave.html
Adobe Photoshop would like to control this computer using accessibility features. Grant access to this application in Security & Privacy preferences, located in System Preferences.
- Select Security & Privacy.
- Click the lock to make changes, then enter your system user name and password for your computer.
- Select Privacy from the top set of tabs, then select Accessibility from the left-hand column of options.
- Click the + (plus) button under the list 'Allow the apps below to control your computer'.
- Navigate to the Applications folder and select the Photoshop application and click Open.
The System Preferences dialog setting for Photoshop should look similar to the image below with Photoshop added and checked: