Hi Metal_Manic,
It is normal for the volume in the AA Web UI to be greyed out when using an Apple device as it is an Apple requirement. You should be able to adjust it with the Apple device in use.
I just rechecked BubbleUPnP and WMP here and not having any problems adjusting volume. It seems you have something else going on. One thing to check is to make sure BubbleUPnP is up to date. Maybe it's possible that you have multiple apps trying to interact with the volume at the same time?
Any more information you can provide would be helpful.
And no there is no way to roll back to the previous version, just factory reset.
Regards,
Steve
