Hi Dennis,
In the
20.4.49 version, we have improved the performance-related issues while
performing Select All/Unselect All operations on the Dropdown Tree component.
Check out the release notes below.
https://ej2.syncfusion.com/angular/documentation/release-notes/20.4.49/?type=all#dropdown-tree
As a
result, we recommend that you update the packages once to the most recent
version. For your reference, we have attached a sample.
https://stackblitz.com/edit/angular-dpuyeg?file=src%2Fapp%2Fapp.component.ts
If the
issue still persists, share with us the exact steps you have followed to
replicate the issue, as well as a sample. Check out the shared sample and get
back to us if you need any further assistance.
Regards,
Indhumathy
L