Purview DLP > Network share groups

Has anyone successfully used this function to exclude internal shares from triggering DLP policy alerts. I recognize that I can use the function to list out specific internal share to be excluded at the DLP policy level, but there are simply too many to list. We've attempted add internal shares with a wild card option:

Example: We've add \\XYZ* to the Network share groups, then under "Copy to a Network Share" > Network share group restrictions > added the group and set the action to "Allow". However, we are still seeing alerts related to the Network share groups set to allow??

My questions:

Is it not possible to wildcard the top level folder (e.g., \\XYZ*) ?
Under Network share group restrictions > added the group and set the action - should the action be "Allow" or "Off". Off does not seem logical to me.