Cannot set the dropdown's value to an unavailable option.

[jp-96]

PXT Bug - FieldUserEnum

Describe the bug

Console message:

Cannot set the dropdown's value to an unavailable option.
Block type: radioMessageCode, Field name: MEMBER, Value: add1

The radio send block's dropdown item is unselected!

To Reproduce
Steps to reproduce the behavior:

1. Create new project on MakeCode for micro:bit
2. Select radio-broadcast extention
3. radio send block
4. See console log

Expected behavior

message1 is selected and there is no warning message.

Screenshots

Edit source code on JavaScript

When convert to Blocks, item is unselected.

[jp-96]

transfered:
microsoft/pxt-arcade#6037