We recently upgraded to erwin Web Portal 2020 R1 and are seeing performance issue on right click | open model. Why so?
This is due to the change in Overview Dashboard in 2020 R1. In Web Portal 2020 R1, the default of dashboard display is entire Model full load so it dynamically computes a lot of statistics of the entire model. Web Portal 2019 does not load all objects by default. In general loading all objects from the data model is the preferred use case as the entire point of the Web Portal is search, list tables, which is the reason for this change.
However, there is a way to customize it. If it is taking too much time to calculate such complex dashboards you can edit the Overview Dashboard by clicking on the top right menu (three vertical dots - > Presentation > Customize) and remove as much as you want from the Overview Dashboard. Once that is done, only the selected options will be loaded.