Custom Property Tab and Performance Issue in Assembly

We recently notice a huge performance issue due to the custom property tab

When the custom property tab is active, selecting and unselecting the face cause a huge delay
image.png
When the custom property tab is not active, selecting and unselecting the face has no issue/delay…
image.png
The custom property template file is stored on user local drive (C:)


Anyone has faced similar issue before?

Edit: For some reason selecting a face with the custom property tab active is stressing out the processor/CPU

Hrm I don’t think I’ve ever encountered that panel before

I don’t have that problem on 2020 SP5, but I don’t have most of the other options checked.
image.png

After some checking…
it seem like one of the imported multi-body part has a very high graphic triangle count (253387) which stressed the system…

But i still dont really understand why turning off the custom property tab improve the performance