Write-WinEvent gets "System.Collections.Generic.List`1[System.String]" in Event Message

[endoleg]

When i use Write-WinEvent i get "System.Collections.Generic.List`1[System.String]" in Event Message 8and not my message.

To Reproduce
Steps to reproduce the behavior:
$EventData = [ordered]@{Program = 'MyProgram';ThisEvent = 'This is an event I want to track'; SomethingElse = 'I like the C64'}
Write-WinEvent -LogName "Application" -Provider Userinfo -EventId 999 -EventType Information -EventData $EventData

Expected behavior
{
"Program": "MyProgram",
"ThisEvent": "This is an event I want to track",
"SomethingElse": "I like the C64"
}

Screenshots
If applicable, add screenshots to help explain your problem.

PowerShell Environment (please complete the following information):

• OS: [Windows 10]
• Version [1909]

Additional context
function Write-WinEvent from
https://gist.githubusercontent.com/thedavecarroll/765547120aa1fa801919040f4d5d2046/raw/2def9b386a8eae88bc26726b7d8770c4c1f8452f/EventData.psm1
works