I don't know if it might help but I think that it happened to me because I closed the game and then the pc to quickly, not allowing the game application to shut down correctly.
Concerning the reply duration, I guess they have lots of other things to do with the upcoming expansion. It might just be under investigation among another things.
My level 15 priest that hasn't been played:
14 charges but should be max.
My level 50 wizard after 20 hours offline:
No charges. I wondered if rebirth interfered with rested, but my husband's toon (same level/also on rb) did manage to accrue 4 charges. He was not offline for a straight 20 hours.
Please sent in game bugreports about this, forum is not for reporting bugs. Sometimes a bug is mentioned here so people can check if they have it too and add their data to it, but if it is only reported here and NOT trough bugreport, it will NOT be fixed. They need the logfiles, especially since it is not a bug occurring to all toons/players.
On pc you can sent in a bugreport by hitting ctrl + shift + B, on mobile the option is under menu.
Bugreports do not receive a reply.