@lalanc01 A general rule of thumb for applying any policies to a device is to allow up to 8 hours for the policy to take effect. This is true not just for Windows Update for Business, but for any group policies or CSPs (via Mobile Device Management tool) that you may configure.
Different management tools may have the ability to push these faster or force a connection, but I am not aware of any off the bat. That said, devices typically scan once every 22 hours on average and if an update is found but the policy then changes to make it so that that update is no longer applicable we stop applying it. This means it should be okay that it takes the extra time to apply.