Why is my DR AG database in the "recovery pending" state?
You cannot put one database into multiple availability groups. The likely cause of the recovery pending state is related to your cluster configuration. If you only have two nodes and no file share or disk witness then your cluster can sustain 0 node failures.

If you're testing by shutting down node 1 and you don't have a quorum witness (file share or disk) then node 2's cluster service will stop and the AG will not bring the databases online.

Run a cluster validation to confirm how many node failures the cluster can sustain (needs to be at least 1) and validate your quorum configuration.