Unable to update block blob in Azure Storage Account using REST API

Hi, I am trying to update the content of a block blob using the storage key and a call to the Azure REST API but it fails stating the body length in my call is wrong.

Call:
$AccountName = "Storage account name"
$Sig = "Key of the storage account"
$container = "Name of the container"
$FileName = "Name of the block blob to update"
$Body = "Contains the text that I want to place inside the block blob"

$authhdr = "SharedKey $AccountName`:$sig"
$datestr=((Get-Date).ToUniversalTime()).ToString("R")
$RequestHeader = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
$RequestHeader.Add("Authorization", $authhdr)
$RequestHeader.Add("Content-Type", "text/plain; charset=UTF-8")
$RequestHeader.Add("x-ms-date", $datestr)
$RequestHeader.Add("x-ms-version", "2015-04-05")
$RequestHeader.Add("x-ms-blob-type","BlockBlob")
$RequestHeader.Add("Content-Length",$Body.Length)

Invoke-RestMethod -Method Put -Uri "https://$AccountName.blob.core.windows.net/$container/$FileName" -Body $Body -Headers $RequestHeader -SkipHeaderValidation

Result:
Invoke-RestMethod:
Bad Request
Bad Request - Invalid Content Length
HTTP Error 400. There is an invalid content length or chunk length in the request.

Expected result:

The block blob is update with the content of the $Body variable.

This was working fine about 2 months ago, I was able to test it and now I get this problem about the size of the body.

Does anyone have the same problem?

Thank you!

No repository file or test is identified. Start with the PowerShell Invoke-RestMethod PUT call and the Azure Blob Storage REST API request details; reproduce the invalid content-length response and determine what request behavior is expected for the block blob update.

Written by the indexing model from the issue text.