### Bug report
The MultiSelect TagHelper is rendered as a DropDownList and does not allow multiple selections.
### Reproduction of the problem
https://demos.telerik.com/aspnet-core/multiselect/tag-helper
### Expected/desired behavior
The MultiSelect TagHelper should allow multiple selections.
### Environment
* **Kendo UI version: 2021.3.914
* **jQuery version: 1.12.4
* **Browser: [all]