powershell hash table is not overwriting location value at deployment time

[pchettri3]

`
$params = @{
name = "apptestpc" + (get-date).ToString("yyyyMMddhhmmss")
Location = 'eastus'
environment = 'DR' # use DEV, Prod, UAT, Test, Services
subscription = 'xxxxx'
TemplateFile = "${scriptDirectory}\main.bicep"
TemplateParameterFile = "${scriptDirectory}\varparam.json"
appInstanceName = "pctestappkpg1"#,pctestappkpg2,pctestappkpg3"
sitesResourceGroup = "site-aps-rg"
networkResourceGroup = "net-eus-ntw-rg"
subnetname = "xxx-sn"
Linuxversion = "PHP|8.2" # 'TOMCAT|8.5-java11' 'TOMCAT|10.0-java17' 'JBOSSEAP|7-java17' TOMCAT|8.5-java11 "PHP|8.2"
}

New-AzSubscriptionDeployment @params -Verbose
`

Why powershell does not replace location value in \varparam.json or main or module ?

This is how it looks in parameter file (same case and no spaces) -
"Location": {
"value": "westus3"
},