WMDP - Work user mobil display settings criteria

Good morning everyone,

after a lot of tries I'm finally reaching out here and want to ask what experience you had already with the "Criteria" column in AX2012 in 

Warehouse Management --> Setup --> Mobile Device --> Work mobile device display settings 

In particular the Criteria field.

We want to have different CSS files based on the Broweser/ UserAgent. 

Based on Microsoft's documentation the Criteria needs to be a .NET regular expression in order to work:

https://docs.microsoft.com/en-us/dynamics365/unified-operations/supply-chain/warehousing/change-warehouse-mobile-device-displays

So I made a project in Visual studio to test my Regular expression:

string input = "Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.1;+Windows+Phone+6.5.3.5)";
string pattern = "Windows\\+Phone";

Regex reg = new Regex(pattern);

bool test = reg.IsMatch(input);

The bool "test" resturns true, but when using this one in AX as criteria as follows:

Request.UserHostAddress=.*|HostName=.*|Request.UserAgent=Windows\\+Phone

It returns that i cannot find any CSS file. 

Is there any different formatting what needs to be taken into consideration when entering it in AX?

Thanks for your help!