My 2 cents:
In the office environment, you are using a proxy server. The Acceptance environment is not using/not able to use the office proxy. In Mendix you can set in Settings -> Configurations -> Server Tab -> Extra JVM parameters
-Dhttp.proxyHost=HostName -Dhttp.proxyPort=Port -Dhttp.proxyUser=Domain\username -Dhttp.proxyPassword=passwor
I hope this is it. I should know more if this didn't solve it.
Go Make IT