Thanks for getting back to us here in the Community. Allow me to chime in and provide additional information concerning your QuickBooks Desktop for Mac 2019.
QuickBooks Server is an app that you need to install and run on the host computer. It's mainly for allowing multi-user access and sharing the company file through the network.
There are several factors why your QuickBooks program is running slow. Like one of our peer users, I also want to know the OS of the computer you're currently using for sharing.
Please take time to check the system requirements for the latest version to ensure smooth navigation. You can also try performing the basic troubleshooting for possible data damage.
For the detailed steps, you can visit the article I recommend on this: Resolving Potential Data Issues.
Please keep in touch with me here should you need any further assistance with using the QuickBooks program. The Community will be sure to get back to you.