This isn't related to Trail version.

Where are you scrolling ? I think your database is stored on local server as you're using the trail version. It might be possible that your system is slow.

What is your system configuration and how old is your os ?

Is your server stored locally or on remote location. Also, create a extract of data and then check if performance improve.

If its working fine with extract then switch to extract mode. This is the best option. If this is not possible then perform the join operations in the database itself instead in Tableau.Use indexes on relevant fields in database to optimize the join operations.