If mouse gestures or keyboard input aren’t registering on your Mac, try the following steps:
Reset the Remote Management Service
Follow this guide to reset the Remote Management Service. Ensure that both the Observe and Control options are enabled.
Multiple Displays on the Remote Mac
If multiple displays are connected to the remote Mac, a known macOS bug might prevent the cursor from moving. For more information and workarounds, check out this article.
Check Your Settings
Interaction Mode
Ensure that Control mode is selected in your connection settings, as Observe mode will not allow mouse or keyboard input. Screens will remember your last used mode, so if you ended your last session in Observe mode, it will default to that in your next session. You can change this setting through the toolbar action button (located at the far-right of the toolbar) and select Interaction Mode.
Also, ensure that Start in Observe Mode is not enabled in your connection settings.
For more details about interaction modes, please refer to this article.
Cursor Control Mode
For iPad or iPhone users, choose the appropriate Cursor Control Mode. If you want to control your remote Mac like a trackpad but have Screens set to Touch mode, you should switch to Trackpad mode. More details can be found in the Cursor Control Modes article.
Installed Software on Remote Mac
Certain software, such as mouse jigglers or applications that modify or interact with the keyboard, can interfere with mouse and keyboard control. Try disabling any such software and then attempt to connect again. If you’re able to connect successfully after disabling the software, it indicates that the installed software is incompatible with screen sharing.