We filed in December also.
PD 12/30/22
AR1 12/30/22 from Nebraska
We got a similar email that they had taken action on our case about 5 days later, and there were never any updates online.
A few days ago, I asked Emma to connect to live chat, and I discovered we had been moved to Vermont. I suspect this is the “action taken on our case”.
We also sent K3 01/23/23, which was received in Texas 01/25/23, but we have not received any receipt notice so far.