we use a BlazoredTypeahead control inside a TelerikWindow and have this problem.
When you open the result dropdown of BlazoredTypeahead and click on the scrollbar in the result dropdown, the result dropdown is closed suddenly.
This only happens when a BlazoredTypeahead control is inside a TelerikWindow. If I remove the Telerik Window everything works as expected.
Attached is a running example, which demonstrates the issue. In the example just click on the "New" button in the grid, this will open the TelerikWindow, which contains the BlazoredTypeahead control.
Thanks for your help.