Favorites / Hidden not syncing

FireTV is version 3.5.0.

I just edited some favorites and hidden channels on my 2 tuners, and since the guide did not update on the first FireTV I checked, I went into the settings on that client to sources, and tried to 'Sync Favorites/Hidden' for each tuner. When I did this, all the channels for the tuner I synced disappeared. I am importing from the source, and the Favorites / Hidden channels at the server level are still intact, so something is not getting to the client.

If I force stop the app and clear the cache and go back into it, the channels for both tuners are back, but there are still no favorites or hidden channels. But then synchronizing again repeats the same thing.

I am hesitant about trying the 'Refresh Source' because I am pretty sure that triggers a channel rescan on the tuner, which I don't want to do (the reason I am hiding more channels is because we have been picking up channels from the edge of another market which we don't want).

I had the same problem this morning on a Firestick client (primarily for hidden stations on the HDHR OTA at the server side). I attempted to sync the client with the server/source, and it simply would not do it, the client continued to show all the server side hidden HDHR stations in the guide. I ended up configuring the hidden stations manually, one at a time.

I tried forcing Channels to stop, clearing data, clearing cache, resyncing, just wouldn't seem to take.