Unable to create a new Conditional Access authentication context object

Describe the bug

When trying to create a new authentication context I get an error

New-MgIdentityConditionalAccessAuthenticationContextClassReference_CreateExpanded: Specified method is not allowed. Try GET, PATCH, DELETE

I tried to create it directly and using the BodyParameter.

New-MgIdentityConditionalAccessAuthenticationContextClassReference -DisplayName 'test context' -Id 'c2' -IsAvailable

and using the example in the MS docs link below.

This is an article for the beta module, the prod one doesn't have an example for whatever reason.

https://learn.microsoft.com/en-us/powershell/module/Microsoft.Graph.Beta.Identity.SignIns/New-MgBetaIdentityConditionalAccessAuthenticationContextClassReference?view=graph-powershell-beta#example-1-code-snippet

Expected behavior

Expected behavior is that the authentication context object gets created with the object id, name displayed.

How to reproduce

Run either of those:

New-MgIdentityConditionalAccessAuthenticationContextClassReference -DisplayName 'test authentication context' -Id 'c2' -IsAvailable

$AuthenticationContextBody = @{
	id = 'c2'
	displayName = 'test authentication context'
	isAvailable = $true
}

New-MgBetaIdentityConditionalAccessAuthenticationContextClassReference -BodyParameter $AuthenticationContextBody

SDK Version

2.33.0

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

New-MgIdentityConditionalAccessAuthenticationContextClassReference_CreateExpanded: Specified method is not allowed. Try GET, PATCH, DELETE

Status: 405 (MethodNotAllowed)
ErrorCode: MethodNotAllowed
Date: 2025-12-11T09:21:28

Headers:
Cache-Control                 : no-cache
Vary                          : Accept-Encoding
Strict-Transport-Security     : max-age=31536000
request-id                    : 8003e512-0000-0000-0000-a800072bd353
client-request-id             : 000c793b-0000-0000-0000-a8005b5050b2
x-ms-ags-diagnostic           : {"ServerInfo":{"DataCenter":"Sweden Central","Slice":"E","Ring":"3","ScaleUnit":"002","RoleInstance":"GV3PEPF00002BC3"}}
Date                          : Thu, 11 Dec 2025 09:21:27 GMT


  Recommendation: See service error codes: https://learn.microsoft.com/graph/errors

Configuration

PSVersion                      7.5.4
PSEdition                      Core
OS                             Microsoft Windows 10.0.22631

Other information

No response

Start by reproducing the 405 response with New-MgIdentityConditionalAccessAuthenticationContextClassReference and the BodyParameter example from the linked Microsoft Graph documentation. Compare the production and beta cmdlets and their documented HTTP operations. Done means the supported create flow successfully creates an authentication context with the supplied id, display name, and availability settings.