Hi @Mik3ymike
Welcome to the Sonos Community!
Sorry to hear of this issue you are having with lip sync on your DirecTV box.
The first thing I would try is unplugging the DirecTV box and the TV from power for a full minute, to see if that helps (I would not be surprised to hear if it does, but this is really just on the off-chance that it does).
Regarding the HD Fury Arcana, my own experience is limited to buying a faulty one that did not work at all and returning it, but yes - it should allow you to hear the output from TV apps on your Arc. Please note, however, that if the issue is with the DirecTV box, the Arcana will not fix it, though it will give you an option to adjust the delay, just as your TV and Arc already do - the issue lies when the audio is delayed as compared to the picture, as delaying the audio will only make matters worse.
If the audio is in advance of the picture, however, please go to Settings icon » oroom with Arc] » TV Dialogue Sync and increase the delay until audio and video are synced. Please note, however, that this would need to be adjusted back when playing TV apps.
I hope this helps.
Set your TV to these settings:
HDMI-eARC Mode: Off
Digital Output Audio Format: Pass-Through