Welcome to the community and thank you for asking your first question. When Lacerte is running slowly, this is our goto knowledge base to help resolve it:

Lacerte Program Is Running Slow

https://accountants-community.intuit.com/articles/1862098-lacerte-program-is-running-slow

Also, if it is running fine on the local drive and it is just when running from the network, this usually means that there is an issue between the Workstations and the Server. I would also take a look at this knowledge base for Firewall/Antivirus:

Firewall and Anti-Virus Software Configuration for Lacerte Tax

https://accountants-community.intuit.com/articles/1861054-firewall-and-anti-virus-software-configura...