With a TV source, there will always be a delay when grouping a Play:1 with the Beam. They should play in sync with music when grouped.
Only way to have them in sync for TV is to have two Play:1s and add them as surrounds to the Beam. This will then allow the remote to control volume on all speakers as they are treated as one room, but the Play:1s will only output the surround channels, not the sound output you get from grouping.
Are you trying to make a stereo pair out of one Beam and one Play:1?
This is not possible, and rightly so; as it would sound terrible.
Thank you for your help Mr T! Much appreciated.