Select component with tag mode inputs wrong value for keydown.enter event

[roro-vetro]

Reproduction link

https://stackblitz.com/edit/ng-zorro-antd-start?file=package.json

Steps to reproduce

You can even reproduce it in demo of https://ng.ant.design/components/select/en

1. Choose a select which nzMode is tags
2. When the select is EMPTY, type a value that is already in the options(like a10, b11)
3. Press enter.
4. You can find the value's last character in the select is removed. For example, if you type 'a10' and press enter, it's 'a1' shows up in select instead of 'a10'.
5. It only happens when select is empty and first input.

What is expected?

What user types, like 'a10' or 'b11'

What is actually happening?

'a1', 'b1'

Environment	Info
ng-zorro-antd	9.1.0
Browser	chrome