Q: After un-pairing, my trackpad pairs as a mouse

Hello maxed,

Thanks for asking your question here in the Apple Support Communities. I understand your need to have the trackpad gestures working as expected, even if you have to use the trackpad paired to another device, then pair it again to your computer. You definitely want to be able to do this without having to restart the Mac each time. I would like to offer a few things for you to check to get this working as expected for you.

The first thing we need to do is to ensure there is no interference. You can use this article to ensure other items in your house or office are not causing interference with this Bluetooth 4.0 connection. Potential sources of Wi-Fi and Bluetooth interference. This second article also goes over some instances where people had issues with other Bluetooth devices causing interference. Please check this article: Bluetooth: Unreliable wireless performance may occur when USB 3.0 external devices are close.

Once you are sure all the potential causes of interference are removed, you can check that you are setting everything up correctly using these two articles. Using a Bluetooth mouse, keyboard, or trackpad with your Mac & If your Apple wireless mouse, keyboard, or trackpad aren‘t working as expected. Both have great information to verify the set-up, which may solve your issues today. In the second article, I would start with the first and third sections if the computer incorrectly names it a mouse still. 

Lastly, you may want to see if the trackpad works properly in safe mode and a test user. Safe mode will tell us if the issue is related to a startup item or plugins. A test user will let us know if the issue is isolated to your account, or system wide. To enter safe mode, please check this article: Try safe mode if your Mac doesn‘t finish starting up. I know the article talks about if the Mac doesn't finish booting, but it will also work to tell you if this issue is caused by some third party plugin or caches. Once in safe mode, try unpairing the trackpad, and then try pairing it again to see if the issue still occurs. If the issue does not occur in safe mode, check the section in that article titled “If an issue doesn't happen in safe mode” for the steps to solve this.

If the issue did still occur in safe mode, please try unpairing and pairing the trackpad in a test user. This article wil help you make a test user: How to test an issue in another user account on your Mac. If the issue only occurs in your main admin user, but not the test user, check the section in that article titled "If an issue happens in only one user account".

Thanks again for bringing up your query here in the Apple Support Communities. Have a great rest of your day.