I am having issue with Mouse scroll speed (extremely slow) on Macbook With universal control.

Hi milay26,

You might be able to adjust the pointer speed on your iPad to get the results you need.

See if the settings suit you:

Change mouse settings on iPad

That can help with adjusting iPad settings for your mouse.

Thanks for using the Apple Support Communities.

Hello milay26,

Let's use the steps below to make sure that your Mac is all up to date:

Before following these steps, it's a good idea to back up your Mac.

1. From the Apple menu  in the corner of your screen, choose System Settings or System Preferences.

• If you chose System Settings, click General on the left side of the window. Then click Software Update on the right.

• If you chose System Preferences, click Software Update in the window.

4. Software Update then checks for new software. 

• If Software Update finds new software, click the button to install it. The button might be named Update Now, Upgrade Now, Install Now, or Restart Now, for example. You might then be asked to enter your administrator password.

• If Software Update says that your Mac is up to date, then no new software is currently available for your Mac model. Software Update shows only software that is compatible with your Mac.

You can also find those steps in this resource: Update macOS on Mac - Apple Support

You'll also want to verify that your iPad is up to date: Update your iPhone or iPad - Apple Support

1. Back up your device using iCloud or your computer.

2. Plug your device into power and connect to the internet with Wi-Fi.

3. Go to Settings > General, then tap Software Update.

4. If you see more than one software update option available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

Updating should help to further isolate a potential conflict.

Should that behavior still persist, you'll want to reach out to Apple Support: Contact - Official Apple Support They'll be in the best position to look into this further.

Take care.