Need to warmup your SharePoint sites, try this small script

#Get SharePoint PowerShell commands#
asnp *sharepoint*

#Query webapplications #

$webapps = get-spwebapplication -IncludeCentralAdministration
foreach ($app in $webapps)
{
$sites = get-spsite -webapplication $app.url -Limit ALL
foreach ($site in $sites)
{
#write-host $site.Url;
foreach ($web in $site.AllWebs)
{
#write-host $web.Url;
$r = Invoke-WebRequest -URI $web.Url -UseDefaultCredentials
}
}
}

Write-Host “Done”